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 A378802 #11 Dec 08 2024 02:35:24
%S A378802 0,4,56,660,7280,77520,807576,8288280,84146400,847289520,8476605280,
%T A378802 84362730452,836022413616,8255176274800,81266247493200,
%U A378802 797911337890800,7816430993273280,76417576884236016,745777615780501920,7266758081613043600,70706322844243486400,687103929058903836480
%N A378802 a(n) = n * binomial(4*n, n).
%H A378802 Amiram Eldar, <a href="/A378802/b378802.txt">Table of n, a(n) for n = 0..500</a>
%H A378802 Necdet Batir and Anthony Sofo, <a href="http://dx.doi.org/10.1016/j.amc.2013.05.053">On some series involving reciprocals of binomial coefficients</a>, Appl. Math. Comp., Vol. 220 (2013), pp. 331-338.
%F A378802 a(n) = n * A005810(n).
%F A378802 a(n) = A374522(n) + n.
%F A378802 a(n) == 0 (mod 4).
%F A378802 Sum_{n>=1} 1/a(n) = A225847.
%F A378802 Sum_{n>=1} (-1)^n/a(n) = A229703.
%t A378802 a[n_] := n * Binomial[4*n, n]; Array[a, 25, 0]
%o A378802 (PARI) a(n) = n * binomial(4*n, n);
%Y A378802 Cf. A005810, A225847, A229703, A374522.
%K A378802 nonn,easy
%O A378802 0,2
%A A378802 _Amiram Eldar_, Dec 07 2024