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 A376724 #13 Oct 03 2024 13:22:07
%S A376724 1,0,0,2,2,0,3,10,3,4,28,28,9,60,126,66,115,396,403,292,1007,1724,
%T A376724 1281,2366,5736,6128,6468,16202,24888,23664,43055,85158,97156,124044,
%U A376724 257474,374538,421785,740324,1294129,1577756,2217676,4085272,5813587,7319572,12370630
%N A376724 Expansion of 1/((1 - x^3 - x^4)^2 - 4*x^7).
%H A376724 <a href="/index/Rec#order_08">Index entries for linear recurrences with constant coefficients</a>, signature (0,0,2,2,0,-1,2,-1).
%F A376724 a(n) = 2*a(n-3) + 2*a(n-4) - a(n-6) + 2*a(n-7) - a(n-8).
%F A376724 a(n) = (1/2) * Sum_{k=0..floor(n/3)} binomial(2*k+2,2*n-6*k+1).
%o A376724 (PARI) my(N=50, x='x+O('x^N)); Vec(1/((1-x^3-x^4)^2-4*x^7))
%o A376724 (PARI) a(n) = sum(k=0, n\3, binomial(2*k+2, 2*n-6*k+1))/2;
%Y A376724 Cf. A182890, A376723, A376725.
%Y A376724 Cf. A376727, A376730.
%K A376724 nonn
%O A376724 0,4
%A A376724 _Seiichi Manyama_, Oct 02 2024