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 A029993 #16 Feb 10 2025 20:02:46
%S A029993 0,1,4,16,64,100,121,400,1024,1600,2500,3249,4096,6400,25600,40000,
%T A029993 118336,160000,250000,302500,310249,532900,1000000,1893376,2050624,
%U A029993 3579664,5769604,6007401,6250000,7573504,7845601,11833600
%N A029993 Squares which are palindromes in base 7.
%H A029993 Seiichi Manyama, <a href="/A029993/b029993.txt">Table of n, a(n) for n = 1..100</a>
%H A029993 Patrick De Geest, <a href="https://www.worldofnumbers.com/nobase10pg2.htm">Palindromic Squares in bases 2 to 17</a>
%F A029993 a(n) = A029992(n)^2. - _Seiichi Manyama_, Oct 16 2021
%t A029993 pal7Q[n_]:=Module[{idn7=IntegerDigits[n,7]},idn7==Reverse[idn7]]; Select[Range[0,3500]^2,pal7Q] (* _Harvey P. Dale_, Dec 15 2011 *)
%Y A029993 Squares which are palindromes in base b: A029983 (b=2), A029985 (b=3), A029987 (b=4), A029989 (b=5), A029991 (b=6), this sequence (b=7), A029806 (b=8), A029995 (b=9), A002779 (b=10), A029997 (b=11), A029738 (b=12), A029999 (b=13), A030074 (b=14), A030075 (b=15), A029734 (b=16).
%Y A029993 Cf. A029992.
%K A029993 nonn,base
%O A029993 1,3
%A A029993 _Patrick De Geest_