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 A029964 #20 Aug 11 2024 14:41:30
%S A029964 0,1,2,3,4,5,6,8,121,171,242,292,16561,65656,2137312,4602064,6597956,
%T A029964 6958596,9470749,61255216,230474032,466828664,485494584,638828836,
%U A029964 657494756,858474858,25699499652,40130703104,45862226854
%N A029964 Palindromic in bases 7 and 10.
%H A029964 Robert G. Wilson v, <a href="/A029964/b029964.txt">Table of n, a(n) for n = 1..65</a>
%H A029964 P. De Geest, <a href="https://www.worldofnumbers.com/nobase10.htm">Palindromic numbers beyond base 10</a>
%t A029964 NextPalindrome[n_] := Block[{l = Floor[ Log[10, n] + 1], idn = IntegerDigits[n]}, If[ Union[idn] == {9}, Return[n + 2], If[l < 2, Return[n + 1], If[ FromDigits[ Reverse[ Take[idn, Ceiling[l/2]] ]] FromDigits[ Take[idn, -Ceiling[l/2]]], FromDigits[ Join[ Take[idn, Ceiling[l/2]], Reverse[ Take[idn, Floor[l/2]] ]]], idfhn = FromDigits[ Take[idn, Ceiling[l/2]]] + 1; idp = FromDigits[ Join[ IntegerDigits[idfhn], Drop[ Reverse[ IntegerDigits[idfhn]], Mod[l, 2]] ]]] ]]]; palQ[n_Integer, base_Integer] := Block[{idn = IntegerDigits[n, base]}, idn == Reverse[idn]]; l = {0}; a = 0; Do[a = NextPalindrome[a]; If[ palQ[a, 7], AppendTo[l, a]], {n, 2000000}]; l (* _Robert G. Wilson v_, Sep 30 2004 *)
%t A029964 Select[Range[0, 10^5],
%t A029964 PalindromeQ[#] && # == IntegerReverse[#, 7] &] (* _Robert Price_, Nov 09 2019 *)
%Y A029964 Cf. A007632, A007633, A029804, A029961, A029962, A029963, A029965, A029966, A029967, A029968, A029969, A029970.
%K A029964 nonn,base
%O A029964 1,3
%A A029964 _Patrick De Geest_