Quasi-Over-Squares of the form n^2 + (n+1)
Not long after I submitted the numbers of the form n + (n+1)^2 under A028387, Neil Sloane pointed out to me that his Integer Sequence A028392 is the complement of the former. This means that what's missing in the first sequence appears in the second. The formula of the complement series is n + [sqrt(n)]. The square brackets indicate that the integer part of the real number in it must be considered.
0,1,2,3,4,5,6,7,8,9,10,11,12,13,14,15,16,17,18,19,20,21,22,23,24,25,26,27,28,29,30,
31,32,33,34,35,36,37,38,39,40,41,42,43,44,45,46,47,48,49,50,51,52,53,54,55,56,57,58
When one subtracts the second part [sqrt(n)] from n ( See John Mellor's entry A028391 ) then another curiosity shows up that also relates n [sqrt(n)] to the numbers of the form n + (n+1)^2. Each number preceding the couple of two identical numbers is also of the form n + (n+1)^2. See for yourself :
0,0,1,2,2,3,4,5,6,6,7,8,9,10,11,12,12,13,14,15,16,17,18,19,20,20,21,22,23,24,25,
26,27,28,29,30,30,31,32,33,34,35,36,37,38,39,40,41,42,42,43,44,45,46,47,48,49,50
One infinite expanding patterns immediately shows up :
10 + 112 = 131
100 + 1012 = 10301
1000 + 10012 = 1003001
10000 + 100012 = 100030001
Palindromes Quasi_Under_Squares can only end with one of the following digits 1, 5 or 9 !
There exist no such palindromes of length 8, 16, 20.
My search program searched for palindromes exhaustively upto length 33
The Table

| Index Nr |
Base Square Expression | |
| Palindromic Sums of Powers of Consecutive Integers | Length |
| | | |
Sums of Powers [1,2] of TWO Consecutive Integers or Quasi_Under_Squares |
| 120 |
39.213.318.281.545.047 | 17 |
| 1.537.684.330.649.755.115.579.460.334.867.351 | 34 |
| 119 |
39.077.257.615.763.875 | 17 |
| 1.527.032.062.768.775.885.778.672.602.307.251 | 34 |
| 118 |
35.809.584.980.401.740 | 17 |
| 1.282.326.376.468.613.993.168.646.736.232.821 | 34 |
| 117 |
31.248.325.265.075.654 | 17 |
| 976.457.831.871.965.535.569.178.138.754.679 | 33 |
| 116 |
10.000.000.000.000.000 | 17 |
| PRIME 100.000.000.000.000.030.000.000.000.000.001 | 33 |
| 115 |
3.849.104.088.659.517 | 16 |
| 14.815.602.285.335.422.453.358.220.651.841 | 32 |
| 114 |
3.752.868.400.303.992 | 16 |
| 14.084.021.230.000.255.200.003.212.048.041 | 32 |
| 113 |
3.473.560.140.754.732 | 16 |
| 12.065.620.051.440.044.004.415.002.656.021 | 32 |
| 112 |
2.358.576.798.224.286 | 16 |
| 5.562.884.513.121.931.391.213.154.882.655 | 31 |
| 111 |
1.412.890.844.107.342 | 16 |
| 1.996.260.537.362.361.632.637.350.626.991 | 31 |
| 110 |
1.400.359.109.515.442 | 16 |
| PRIME 1.961.005.635.602.885.882.065.365.001.691 | 31 |
| 109 |
1.397.804.508.310.230 | 16 |
| 1.953.857.443.452.408.042.543.447.583.591 | 31 |
| 108 |
1.220.422.583.985.392 | 16 |
| 1.489.431.283.501.584.851.053.821.349.841 | 31 |
| 107 |
1.142.090.725.619.310 | 16 |
| 1.304.371.225.545.645.465.455.221.734.031 | 31 |
| 106 |
1.049.921.608.476.002 | 16 |
| PRIME 1.102.335.383.944.838.384.493.835.332.011 | 31 |
| 105 |
1.003.691.398.020.997 | 16 |
| 1.007.396.422.461.346.431.642.246.937.001 | 31 |
| 104 |
1.000.000.000.000.000 | 16 |
| 1.000.000.000.000.003.000.000.000.000.001 | 31 |
| 103 |
430.721.068.556.660 | 15 |
| 185.520.638.898.592.295.898.836.025.581 | 30 |
| 102 |
309.637.329.125.363 | 15 |
| 95.875.275.587.889.298.878.557.257.859 | 29 |
| 101 |
123.245.184.901.447 | 15 |
| 15.189.375.601.392.229.310.657.398.151 | 29 |
| 100 |
122.258.874.462.692 | 15 |
| 14.947.232.384.884.648.848.323.274.941 | 29 |
| 99 |
103.594.624.078.972 | 15 |
| 10.731.846.138.063.836.083.164.813.701 | 29 |
| 98 |
100.000.000.000.000 | 15 |
| PRIME 10.000.000.000.000.300.000.000.000.001 | 29 |
| 97 |
71.003.776.901.961 | 14 |
| 5.041.536.334.343.663.434.336.351.405 | 28 |
| 96 |
31.375.435.997.608 | 14 |
| PRIME 984.417.984.040.090.040.489.714.489 | 27 |
| 95 |
10.000.000.000.000 | 14 |
| 100.000.000.000.030.000.000.000.001 | 27 |
| 94 |
4.342.164.720.885 | 13 |
| 18.854.394.463.311.336.449.345.881 | 26 |
| 93 |
3.031.211.772.419 | 13 |
| 9.188.244.809.260.629.084.428.819 | 25 |
| 92 |
2.346.319.275.006 | 13 |
| 5.505.214.140.271.720.414.125.055 | 25 |
| 91 |
1.389.789.688.542 | 13 |
| 1.931.515.378.381.838.735.151.391 | 25 |
| 90 |
1.361.229.261.212 | 13 |
| 1.852.945.101.583.851.015.492.581 | 25 |
| 89 |
1.233.391.513.747 | 13 |
| 1.521.254.626.186.816.264.521.251 | 25 |
| 88 |
1.132.222.222.132 | 13 |
| 1.281.927.160.292.920.617.291.821 | 25 |
| 87 |
1.000.000.000.000 | 13 |
| 1.000.000.000.003.000.000.000.001 | 25 |
| 86 |
713.321.230.881 | 12 |
| 508.827.178.427.724.871.728.805 | 24 |
| 85 |
707.787.945.801 | 12 |
| 500.963.776.223.322.677.369.005 | 24 |
| 84 |
391.072.107.747 | 12 |
| 152.937.393.458.854.393.739.251 | 24 |
| 83 |
330.896.531.697 | 12 |
| 109.492.514.690.096.415.294.901 | 24 |
| 82 |
308.614.186.963 | 12 |
| PRIME 95.242.716.395.759.361.724.259 | 23 |
| 81 |
304.837.396.093 | 12 |
| 92.925.838.057.675.083.852.929 | 23 |
| 80 |
236.020.325.651 | 12 |
| 55.705.594.121.112.149.550.755 | 23 |
| 79 |
234.608.196.391 | 12 |
| 55.041.005.814.541.850.014.055 | 23 |
| 78 |
225.562.844.356 | 12 |
| 50.878.596.754.645.769.587.805 | 23 |
| 77 |
100.000.000.000 | 12 |
| PRIME 10.000.000.000.300.000.000.001 | 23 |
| 76 |
36.648.687.110 | 11 |
| 1.343.126.266.996.626.213.431 | 22 |
| 75 |
13.772.991.538 | 11 |
| PRIME 189.695.295.919.592.596.981 | 21 |
| 74 |
10.000.000.000 | 11 |
| 100.000.000.030.000.000.001 | 21 |
| 73 |
3.158.325.174 | 10 |
| 9.975.017.914.197.105.799 | 19 |
| 72 |
3.018.331.094 | 10 |
| 9.110.322.602.062.230.119 | 19 |
| 71 |
3.004.166.888 | 10 |
| 9.025.018.699.968.105.209 | 19 |
| 70 |
2.361.405.226 | 10 |
| 5.576.234.648.464.326.755 | 19 |
| 69 |
2.255.496.516 | 10 |
| 5.087.264.540.454.627.805 | 19 |
| 68 |
2.253.899.681 | 10 |
| 5.080.063.778.773.600.805 | 19 |
| 67 |
2.248.287.096 | 10 |
| 5.054.794.872.784.974.505 | 19 |
| 66 |
1.398.162.767 | 10 |
| 1.954.859.127.219.584.591 | 19 |
| 65 |
1.229.782.822 | 10 |
| 1.512.365.792.975.632.151 | 19 |
| 64 |
1.194.696.280 | 10 |
| 1.427.299.205.029.927.241 | 19 |
| 63 |
1.097.411.265 | 10 |
| 1.204.311.487.841.134.021 | 19 |
| 62 |
1.059.993.227 | 10 |
| 1.123.585.644.465.853.211 | 19 |
| 61 |
1.057.255.302 | 10 |
| 1.117.788.776.778.877.111 | 19 |
| 60 |
1.000.000.0001 + 1.000.000.0012 | 10 |
| 1.000.000.003.000.000.001 | 19 |
| 59 |
340.313.8701 + 340.313.8712 | |
| 115.813.531.135.318.511 | 18 |
| 58 |
326.732.6721 + 326.732.6732 | |
| 106.754.239.932.457.601 | 18 |
| 57 |
307.729.0241 + 307.729.0252 | |
| 94.697.153.135.179.649 | 17 |
| 56 |
303.357.9931 + 303.357.9942 | |
| 92.026.072.827.062.029 | 17 |
| 55 |
134.606.1371 + 134.606.1382 | |
| 18.118.812.521.881.181 | 17 |
| 54 |
106.040.6021 + 106.040.6032 | |
| 11.244.609.590.644.211 | 17 |
| 53 |
100.000.0001 + 100.000.0012 | |
| 10.000.000.300.000.001 | 17 |
| 52 |
23.615.2261 + 23.615.2272 | |
| 557.678.969.876.755 | 15 |
| 51 |
11.373.4401 + 11.373.4412 | |
| 129.355.171.553.921 | 15 |
| 50 |
10.946.6701 + 10.946.6712 | |
| PRIME 119.829.616.928.911 | 15 |
| 49 |
10.000.0001 + 10.000.0012 | |
| 100.000.030.000.001 | 15 |
| 48 |
3.267.3251 + 3.267.3262 | |
| 10.675.422.457.601 | 14 |
| 47 |
3.126.7541 + 3.126.7552 | |
| 9.776.599.956.779 | 13 |
| 46 |
3.040.4041 + 3.040.4052 | |
| 9.244.065.604.429 | 13 |
| 45 |
2.356.5311 + 2.356.5322 | |
| 5.553.245.423.555 | 13 |
| 44 |
2.346.3661 + 2.346.3672 | |
| 5.505.440.445.055 | 13 |
| 43 |
1.334.1071 + 1.334.1082 | |
| 1.779.845.489.771 | 13 |
| 42 |
1.202.8051 + 1.202.8062 | |
| PRIME 1.446.743.476.441 | 13 |
| 41 |
1.172.8351 + 1.172.8362 | |
| 1.375.545.455.731 | 13 |
| 40 |
1.099.2651 + 1.099.2662 | |
| 1.208.386.838.021 | 13 |
| 39 |
1.060.6021 + 1.060.6032 | |
| 1.124.879.784.211 | 13 |
| 38 |
1.000.0001 + 1.000.0012 | |
| 1.000.003.000.001 | 13 |
| 37 |
987.4431 + 987.4442 | |
| 975.046.640.579 | 12 |
| 36 |
709.7811 + 709.7822 | |
| 503.791.197.305 | 12 |
| 35 |
308.8631 + 308.8642 | |
| 95.397.279.359 | 11 |
| 34 |
236.0261 + 236.0272 | |
| 55.708.980.755 | 11 |
| 33 |
234.5661 + 234.5672 | |
| 55.021.912.055 | 11 |
| 32 |
110.6651 + 110.6662 | |
| 12.247.074.221 | 11 |
| 31 |
100.0001 + 100.0012 | |
| 10.000.300.001 | 11 |
| 30 |
96.4391 + 96.4402 | |
| 9.300.770.039 | 10 |
| 29 |
95.6031 + 95.6042 | |
| 9.140.220.419 | 10 |
| 28 |
32.6721 + 32.6732 | |
| 1.067.557.601 | 10 |
| 27 |
31.4741 + 31.4752 | |
| PRIME 990.707.099 | 9 |
| 26 |
30.8341 + 30.8352 | |
| 950.828.059 | 9 |
| 25 |
30.4041 + 30.4052 | |
| 924.494.429 | 9 |
| 24 |
13.2071 + 13.2082 | |
| 174.464.471 | 9 |
| 23 |
12.6521 + 12.6532 | |
| 160.111.061 | 9 |
| 22 |
10.6021 + 10.6032 | |
| PRIME 112.434.211 | 9 |
| 21 |
10.3251 + 10.3262 | |
| 106.636.601 | 9 |
| 20 |
10.0001 + 10.0012 | |
| PRIME 100.030.001 | 9 |
| 19 |
3.0731 + 3.0742 | |
| 9.452.549 | 7 |
| 18 |
1.3071 + 1.3082 | |
| PRIME 1.712.171 | 7 |
| 17 |
1.1321 + 1.1332 | |
| 1.284.821 | 7 |
| 16 |
1.0001 + 1.0012 | |
| PRIME 1.003.001 | 7 |
| 15 |
4421 + 4432 | |
| 196.691 | 6 |
| 14 |
3801 + 3812 | |
| 145.541 | 6 |
| 13 |
3251 + 3262 | |
| 106.601 | 6 |
| 12 |
1221 + 1232 | |
| 15.251 | 5 |
| 11 |
1171 + 1182 | |
| 14.041 | 5 |
| 10 |
1001 + 1012 | |
| PRIME 10.301 | 5 |
| 9 |
941 + 952 | |
| 9.119 | 4 |
| 8 |
351 + 362 | |
| 1.331 | 4 |
| 7 |
291 + 302 | |
| PRIME 929 | 3 |
| 6 |
211 + 222 | |
| 505 | 3 |
| 5 |
121 + 132 | |
| PRIME 181 | 3 |
| 4 |
101 + 112 | |
| PRIME 131 | 3 |
| 3 |
61 + 72 | |
| 55 | 2 |
| 2 |
21 + 32 | |
| PRIME 11 | 2 |
| 1 |
11 + 22 | |
| PRIME 5 | 1 |
| | | |
| Sums of Powers [2,3] of TWO Consecutive Integers |
| 5 |
1.001.0002 + 1.001.0013 | |
| 1.003.007.009.007.003.001 | 19 |
| 4 |
10.1002 + 10.1013 | |
| PRIME 1.030.709.070.301 | 13 |
| 3 |
1102 + 1113 | |
| 1.379.731 | 7 |
| 2 |
42 + 53 | |
| 141 | 3 |
| 1 |
12 + 23 | |
| 9 | 1 |
| | | |
Sums of Powers [3,4] of TWO Consecutive Integers
Searched upto basenumber 2.000.000 |
| 1 |
?3 + ?4 | |
| ? | ? |
| | | |
| Sums of Powers [4,5] of TWO Consecutive Integers |
| 1 |
14 + 25 | |
| 33 | 2 |
| | | |
| Sums of Powers of THREE Consecutive Integers |
| 1 |
?1 + ?2 + ?3 | |
| ? | ? |
| | | |
| Sums of Powers of FOUR Consecutive Integers |
| 1 |
?1 + ?2 + ?3 + ?4 | |
| ? | ? |
| | | |
| Sums of Powers of FIVE Consecutive Integers |
| 1 |
?1 + ?2 + ?3 + ?4 + ?5 | |
| ? | ? |
In case you are also interested in the primes of these numberforms
check out the following entries in Sloane's table :
%N n + (n+1)^2 is a prime. under A002328.
%N Primes of form n + (n+1)^2. under A002327.
%N n + (n+1)^2 + (n+2)^3 + (n+3)^4 + (n+4)^5 is a prime. under A027830.
%N Primes of form n + (n+1)^2 + (n+2)^3 + (n+3)^4 + (n+4)^5. under A027886.
There are no primes of the form n + (n+1)^2 + (n+2)^3.
All such numbers are divisible by (n+3) twice !
The polynomial can be written as (n+1)*(n+3)*(n+3).
There are no primes of the form n + (n+1)^2 + (n+2)^3 + (n+3)^4.
All such numbers are even !
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