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 A373961 #10 Jun 24 2024 08:47:07
%S A373961 1,2,3,4,5,7,15,44,129,340,804,1742,3550,7009,13835,28033,58993,
%T A373961 128136,282569,622575,1357136,2918449,6204578,13104675,27646776,
%U A373961 58502733,124411595,265807567,569552644,1221316021,2616456236,5595314908,11944318042,25466629978
%N A373961 Number of compositions of 6*n-1 into parts 5 and 6.
%H A373961 <a href="/index/Rec#order_06">Index entries for linear recurrences with constant coefficients</a>, signature (6,-15,20,-15,7,-1).
%F A373961 a(n) = A017837(6*n-1).
%F A373961 a(n) = Sum_{k=0..floor(n/5)} binomial(n+k,n-1-5*k).
%F A373961 a(n) = 6*a(n-1) - 15*a(n-2) + 20*a(n-3) - 15*a(n-4) + 7*a(n-5) - a(n-6).
%F A373961 G.f.: x*(1-x)^4/((1-x)^6 - x^5).
%F A373961 a(n) = A373962(n+1) - A373962(n).
%o A373961 (PARI) a(n) = sum(k=0, n\5, binomial(n+k, n-1-5*k));
%Y A373961 Cf. A107025, A369794, A373962, A373963, A373964.
%Y A373961 Cf. A017837.
%K A373961 nonn,easy
%O A373961 1,2
%A A373961 _Seiichi Manyama_, Jun 23 2024