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 A376728 #10 Oct 03 2024 09:57:21
%S A376728 1,0,0,0,3,1,0,0,5,10,1,0,7,35,21,1,9,84,126,36,12,165,462,330,68,287,
%T A376728 1287,1716,730,533,3004,6435,5022,2045,6293,19449,24329,13345,14008,
%U A376728 50524,92400,76912,47481,120156,294124,354488,237139,299421,823200,1354588
%N A376728 Expansion of (1 + x^4 - x^5)/((1 + x^4 - x^5)^2 - 4*x^4).
%H A376728 <a href="/index/Rec#order_10">Index entries for linear recurrences with constant coefficients</a>, signature (0,0,0,2,2,0,0,-1,2,-1).
%F A376728 a(n) = 2*a(n-4) + 2*a(n-5) - a(n-8) + 2*a(n-9) - a(n-10).
%F A376728 a(n) = Sum_{k=0..floor(n/4)} binomial(2*k+1,2*n-8*k+1).
%o A376728 (PARI) my(N=50, x='x+O('x^N)); Vec((1+x^4-x^5)/((1+x^4-x^5)^2-4*x^4))
%o A376728 (PARI) a(n) = sum(k=0, n\4, binomial(2*k+1, 2*n-8*k+1));
%Y A376728 Cf. A099511, A376726, A376727.
%Y A376728 Cf. A376725, A376731.
%K A376728 nonn
%O A376728 0,5
%A A376728 _Seiichi Manyama_, Oct 03 2024