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[ October 23, 2016 ]
Abhiram R. Devesh (email) searches for the smallest numbers
that when appended by the same amount of digits 1, 3, 7 and 9
generates primes in all four cases.


Please find below the list of primes generated by
appending n_1s, n_3s, n_7s and n_9s to one number k.

Appending 1 time [1,3,7,9] to k=1 generates the primes
[11, 13, 17, 19]
Appending 2 times [1,3,7,9] to k=23 generates the primes
[2311, 2333, 2377, 2399]
so on and so forth

Can you find more cases whereby the number k
is smaller or equal than the appended amount of digits d
(in the table below highlighted in light blue) ?

nk[list of primes]
11[d_n]
223[d_n]
32[d_n]
4325[d_n]
52084[d_n]
6685[d_n]
718166[d_n]
82855[d_n]
928253[d_n]
1045964[d_n]
1190452[d_n]
126239[d_n]
13116863[d_n]
1413103[d_n]
159116[d_n]
161798[d_n]
1791643[d_n]
1832519[d_n]
1972313[d_n]
2035900[d_n]
2131552[d_n]
22276187[d_n]
23736202[d_n]
2430889[d_n]
2532947[d_n]
26505229[d_n]
2726888[d_n]
28139621[d_n]
292426324[d_n]
30381580[d_n]


A000200 Prime Curios! Prime Puzzle
Wikipedia 200 Le nombre 200














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