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 A062131 #8 Mar 20 2025 13:54:17
%S A062131 0,3,3,9,5,15,9,21,9,27,15,27,15,27,21,45,17,51,27,99,99,63,-1,63,27,
%T A062131 99,-1,255,-1,63,45,93,33,99,51,-1,45,-1,63,99,45,-1,63,99,99,-1,-1,
%U A062131 -1,51,-1,255,153,63,99,255,153,63,99,255,153,-1,-1,93,189,65,195,99,-1,85,255,119,387,255,219,13299,-1,387,-1,-1,219
%N A062131 A062129 written in base 10.
%C A062131 Differs from A062130 only for those n, which are palindromes in base 2.
%e A062131 23 -> 23 + 29 = 52 -> 52 + 11 = 63, so a(23) = 63.
%o A062131 (ARIBAS) stop := 500; for k := 0 to 80 do c := 0; m := k; test := true; while test and c < stop do inc(c); m := m + bit_reverse(m); test := m <> bit_reverse(m); end; if c < stop then write(m); else write(-1); end; write(" "); end;
%Y A062131 Cf. A061563, A062129, A062130, A061561.
%K A062131 base,easy,sign
%O A062131 0,2
%A A062131 _Klaus Brockhaus_, Jun 06 2001