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 A052057 #16 Oct 19 2021 10:42:57 %S A052057 0,1,2,3,4,5,6,7,8,9,10,11,12,13,14,15,20,21,22,29,37,54 %N A052057 Numbers k such that the decimal expansion of 2^k contains no palindromic substring except single digits. %C A052057 Sequence is probably finite. Next term, if it exists, exceeds 1170. %C A052057 Next term, if it exists, exceeds 50000. - _Sean A. Irvine_, Oct 18 2021 %e A052057 Record number is 2^54 = 18014398509481984. %t A052057 Select[Range[0, 10^3], NoneTrue[DeleteCases[Subsequences@ IntegerDigits[2^#], _?(Length[#] <= 1 &)], PalindromeQ] &] (* _Michael De Vlieger_, Oct 18 2021 *) %Y A052057 Cf. A000079, A050723, A052058, A052059. %K A052057 nonn,base,more %O A052057 1,3 %A A052057 _Patrick De Geest_, Jan 15 2000 %E A052057 Edited by _Jon E. Schoenfield_, Oct 17 2019