On [ May 25, 1999 ] I found (Patrick De Geest) a larger square that is a palindrome in base 2.
This is at the same time a personal record as never before I discovered
a palindrome of this magnitude namely 65 digits !
4770504939 ² = 22757717373023393721
yielding the following beautiful palindrome when converted into binary
10011101111010011101001110110000000001101110010111001011110111001
Entry in Sloane's Online Encyclopedia is sequence A003166.