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 A385607 #8 Jul 04 2025 10:04:47
%S A385607 1,1,121,721,115921,1254121,175667521,2723150641,328524651841,
%T A385607 6553910658241,694593264839761,16751100559753561,1592929589394223081,
%U A385607 44555491032952142881,3872288533662063462481,121957120480085202781681,9836937778718128127534881,341177468192261294809070401
%N A385607 Diagonal of the rational function 1/(1 - (v^2 + w^2 + x^2 + y^2 + z^2 + v*w*x*y*z)).
%F A385607 a(n) = Sum_{k=0..floor(n/2)} (n+3*k)!/(k!^5 * (n-2*k)!).
%o A385607 (PARI) a(n) = sum(k=0, n\2, (n+3*k)!/(k!^5*(n-2*k)!));
%Y A385607 Cf. A082489, A361636, A361703, A385606.
%K A385607 nonn
%O A385607 0,3
%A A385607 _Seiichi Manyama_, Jul 04 2025