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 A090408 #18 Jun 20 2021 07:31:09
%S A090408 1,36,496,8256,130816,2098176,33550336,536887296,8589869056,
%T A090408 137439215616,2199022206976,35184376283136,562949936644096,
%U A090408 9007199321849856,144115187807420416,2305843010287435776,36893488143124135936,590295810375885520896,9444732965670570950656
%N A090408 a(n) = Sum_{k=0..n} binomial(4n+3,4k).
%H A090408 Seiichi Manyama, <a href="/A090408/b090408.txt">Table of n, a(n) for n = 0..500</a>
%H A090408 <a href="/index/Rec#order_02">Index entries for linear recurrences with constant coefficients</a>, signature (12,64).
%F A090408 a(n) = 2^(1+4*n) - (-1)^n*4^n. - _R. J. Mathar_, Nov 27 2014
%t A090408 Table[Sum[Binomial[4n+3,4k],{k,0,n}],{n,0,20}] (* _Harvey P. Dale_, Feb 12 2020 *)
%Y A090408 Cf. A070775, A001025, A090407, A038503.
%K A090408 easy,nonn
%O A090408 0,2
%A A090408 _Paul Barry_, Nov 29 2003