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 A369816 #19 Aug 17 2025 07:48:12
%S A369816 1,0,0,0,0,1,0,1,0,0,1,0,2,0,1,1,0,3,0,3,1,1,4,0,6,1,4,5,1,10,1,10,6,
%T A369816 5,15,2,20,7,15,21,7,35,9,35,28,22,56,16,70,37,57,84,38,126,53,127,
%U A369816 121,95,210,91,253,174,222,331,186,463,265,475,505,408,794,451,938,770,883,1299,859,1732,1221
%N A369816 Expansion of 1/(1 - x^5 - x^7).
%C A369816 Number of compositions of n into parts 5 and 7.
%H A369816 <a href="/index/Rec#order_07">Index entries for linear recurrences with constant coefficients</a>, signature (0,0,0,0,1,0,1).
%F A369816 a(n) = a(n-5) + a(n-7).
%F A369816 G.f.: 1/((1-x+x^2)*(1+x-x^3-x^4-x^5)). - _R. J. Mathar_, Jul 03 2024
%o A369816 (PARI) my(N=80, x='x+O('x^N)); Vec(1/(1-x^5-x^7))
%o A369816 (PARI) a(n) = sum(k=0, n\7, ((n-2*k)%5==0)*binomial((n-2*k)/5, k));
%Y A369816 Cf. A005709, A017847, A369813, A369814, A369815.
%K A369816 nonn,easy
%O A369816 0,13
%A A369816 _Seiichi Manyama_, Feb 02 2024