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 A358362 #18 Nov 15 2023 03:12:00 %S A358362 1,12,228,3248,56868,846384,14395920,218556096,3662534436,56236646576, %T A358362 933921124752,14445103689408,238434118702864,3706773418885824, %U A358362 60917716297733184,950622015752780544,15571249887287040804,243694280206569964464,3981466564018425521424 %N A358362 a(n) = 16^n * Sum_{k=0..n} (-1)^k*binomial(-1/2, k)^2. %F A358362 a(n) = (64*(2*n - 1)^2*a(n - 2) + (16*n - 4)*a(n - 1)) / n^2. %F A358362 G.f.: hypergeom([1/2, 1/2], [1], -16*x)/(16*x - 1). %F A358362 G.f.: 2*EllipticK(4*I*sqrt(x))/(Pi*(1 - 16*x)). %F A358362 a(n) ~ A014549 * 2^(4*n). - _Vaclav Kotesovec_, Nov 14 2023 %p A358362 a := n -> 16^n*add((-1)^k*binomial(-1/2, k)^2, k = 0..n): %p A358362 seq(a(n), n = 0..19); %t A358362 a[n_] := 16^n * Sum[(-1)^k*Binomial[-1/2, k]^2, {k, 0, n}]; Array[a, 19, 0] (* _Amiram Eldar_, Nov 12 2022 *) %Y A358362 Cf. A358363, A358364, A358365, A367330. %K A358362 nonn %O A358362 0,2 %A A358362 _Peter Luschny_, Nov 12 2022