This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.
%I A331663 #9 Jan 25 2020 06:18:07 %S A331663 95,111,123,125,187,221,335,485,597,629,655,681,697,831,965,1011,1139, %T A331663 1389,1461,1535,1563,1649,1731,1791,1983,2031,2043,2045,2227,2493, %U A331663 2605,2733,2827,2885,2901,3033,3099,3279,3281,3327,3341,3459,3647,3891,4039,4083 %N A331663 Odd composite numbers k with at least one divisor that is not a binary palindrome (A006995) such that the divisors of the binary reversal of k (A030101) are the binary reversals of the divisors of k. %H A331663 Amiram Eldar, <a href="/A331663/b331663.txt">Table of n, a(n) for n = 1..10000</a> %e A331663 95 is a term since the binary representations of its divisors, 1, 5, 19, and 95, are 1, 101, 10011 and 1011111, and their binary reversals, 1, 101, 11001 and 1111101, or 1, 5, 25 and 125 in decimal representation, are the divisors of 125, which is the binary reversal of 95, and 19 and 95 are not binary palindromes. %t A331663 binPalQ[n_] := PalindromeQ @ IntegerDigits[n, 2]; Select[Range[1, 4000, 2], CompositeQ[#] && (Divisors @ IntegerReverse[#, 2]) == IntegerReverse[(d = Divisors[#]), 2] && !AllTrue[Rest[d], binPalQ] &] %Y A331663 Cf. A006995, A030101. %Y A331663 Complement of A329419 with respect to A331662. %Y A331663 A331664 is a subsequence. %K A331663 nonn,base %O A331663 1,1 %A A331663 _Amiram Eldar_, Jan 23 2020