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 A376648 #13 Oct 01 2024 07:19:23
%S A376648 1,0,0,0,1,0,0,0,1,1,0,0,1,1,0,0,1,2,1,0,1,2,1,0,1,3,3,1,1,3,3,1,1,4,
%T A376648 6,4,2,4,6,4,2,5,10,10,6,6,10,10,6,7,15,20,16,12,16,20,16,13,22,35,36,
%U A376648 28,28,36,36,29,35,57,71,64,56,64,72,65,64,92,128,135
%N A376648 a(n) = Sum_{k=0..floor(n/4)} binomial(floor(k/2),n-4*k).
%H A376648 <a href="/index/Rec#order_09">Index entries for linear recurrences with constant coefficients</a>, signature (0,0,0,0,0,0,0,1,1).
%F A376648 G.f.: (1-x^8)/((1-x^4) * (1-x^8-x^9)) = (1+x^4)/(1-x^8-x^9).
%F A376648 a(n) = a(n-8) + a(n-9).
%F A376648 a(n) = A017867(n) + A017867(n-4).
%o A376648 (PARI) a(n) = sum(k=0, n\4, binomial(k\2, n-4*k));
%o A376648 (PARI) my(N=80, x='x+O('x^N)); Vec((1+x^4)/(1-x^8-x^9))
%Y A376648 Cf. A124789, A134816, A376647.
%Y A376648 Cf. A017867.
%K A376648 nonn,easy
%O A376648 0,18
%A A376648 _Seiichi Manyama_, Oct 01 2024