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 A163764 #20 Aug 13 2025 21:28:36
%S A163764 543,651,5187,5973,7161,8463,57057,93093,66063,81003,80199,98553,
%T A163764 130851,160797,216657,259749,347529,561393,565383,726693,882189,
%U A163764 1042587,1084083,922467,1439361,1242927,1768767,1490139,2383227,2857239,2029143,2486169,4517877,6175323
%N A163764 a(n) = sqrt(sigma(2*m^2)), where m = A097023(n), i.e., sigma(2*m^2) is a square.
%H A163764 Amiram Eldar, <a href="/A163764/b163764.txt">Table of n, a(n) for n = 1..200</a> (calculated using the b-file at A097023)
%t A163764 Select[Table[Sqrt[DivisorSigma[1, 2 n^2]], {n, 100000}], IntegerQ[#] &] (* _Tanya Khovanova_, Jun 18 2021 *)
%Y A163764 Cf. A000203, A008847, A097023, A163763.
%K A163764 nonn
%O A163764 1,1
%A A163764 _M. F. Hasler_, Aug 03 2009
%E A163764 a(31)-a(34) from _Amiram Eldar_, Aug 13 2024