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 A263619 #21 Apr 08 2025 13:28:13
%S A263619 4,4,7,7,14,15,20,20,31,31,36,37,56,56,69,70,95,95,113,113,161,162,
%T A263619 193,193,263,264,308,310,415,415,485,486,639,640,738,741,950,950,1082,
%U A263619 1082,1373,1374,1555,1556,1940,1940,2174,2176,2672,2673,2974,2975,3611,3611,3994,3994,4792,4793,5267,5268,6249,6249,6827,6827,8026,8028,8729
%N A263619 Number of palindromic squares with at most n digits.
%H A263619 G. J. Simmons, <a href="/A002778/a002778_2.pdf">Palindromic powers</a>, J. Rec. Math., 3 (No. 2, 1970), 93-98. [Annotated scanned copy] See page 95.
%t A263619 Table[Length[Select[Range[0, Floor[Sqrt[10^n]]], PalindromeQ[#^2] &]], {n, 10}] (* _Robert Price_, Apr 26 2019 *)
%Y A263619 Partial sums of A263618.
%Y A263619 Cf. A002778, A002779, A263616, A263617, A263620.
%K A263619 nonn,base
%O A263619 1,1
%A A263619 _N. J. A. Sloane_, Oct 23 2015
%E A263619 a(13)-a(19) from _Chai Wah Wu_, Oct 24 2015
%E A263619 a(20) from _Robert Price_, Apr 26 2019
%E A263619 a(21)-a(44) using A263618 from _Chai Wah Wu_, Jun 14 2024
%E A263619 a(45)-a(67) added by _Max Alekseyev_, Apr 08 2025