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 A350283 #12 Dec 24 2021 02:34:05
%S A350283 1,0,0,6,76,0,0,7559080,1509040932,0,0,887531129680197018,
%T A350283 3078434842626707386602,0,0,8813577747274880345454470354985336,
%U A350283 509819403352972623999938010230619997952,0,0,6578453931935965721022496238115694708685746283712759572
%N A350283 a(n) is the constant term in the expansion of Product_{k=1..n} (x^k + 1/x^k)^k.
%H A350283 Seiichi Manyama, <a href="/A350283/b350283.txt">Table of n, a(n) for n = 0..50</a>
%F A350283 a(4*n+1) = a(4*n+2) = 0.
%o A350283 (PARI) a(n) = polcoef(prod(k=1, n, (x^k+1/x^k)^k), 0);
%Y A350283 Cf. A350282.
%K A350283 nonn
%O A350283 0,4
%A A350283 _Seiichi Manyama_, Dec 23 2021