A192775 The numbers n^2 as n runs through the numbers which are palindromes in base 2.

0, 1, 9, 25, 49, 81, 225, 289, 441, 729, 961, 1089, 2025, 2601, 3969, 4225, 5329, 7225, 8649, 9801, 11449, 14161, 16129, 16641, 23409, 27225, 35721, 38025, 47961, 53361, 65025, 66049, 74529, 88209, 97969, 105625, 116281, 133225, 145161, 149769, 162409, 182329, 196249, 207025, 221841, 245025, 261121, 263169, 314721, 342225, 400689, 416025, 480249, 514089, 585225

Offset: 1

Author

N. J. A. Sloane, Jul 09 2011

Keywords

• nonn
• base

Crossrefs

Cf. A006995, A057148. See A192776 for these numbers written in base 2.

Programs

Python

def A192775(n):
    if n == 1: return 0
    a = 1<<(l:=n.bit_length()-2)
    m = a|(n&a-1)
    return ((m<Chai Wah Wu, Jul 23 2024