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 A306753 #18 Jun 21 2021 03:01:23
%S A306753 1,1,1,1,1,1,1,1,1,1,2,11,56,221,716,2003,5006,11441,24311,48621,
%T A306753 92380,167980,294121,498751,824506,1341154,2177572,3605251,6249101,
%U A306753 11593726,23138117,48904469,106653707,234305936,510034166,1089810953,2275676459,4637090547
%N A306753 a(n) = Sum_{k=0..n} binomial(k, 9*(n-k)).
%H A306753 Seiichi Manyama, <a href="/A306753/b306753.txt">Table of n, a(n) for n = 0..3506</a>
%H A306753 <a href="/index/Rec#order_10">Index entries for linear recurrences with constant coefficients</a>, signature (9,-36,84,-126,126,-84,36,-9,1,1).
%F A306753 G.f.: (1-x)^8/((1-x)^9 - x^10).
%F A306753 a(n) = 9*a(n-1) - 36*a(n-2) + 84*a(n-3) - 126*a(n-4) + 126*a(n-5) - 84*a(n-6) + 36*a(n-7) - 9*a(n-8) + a(n-9) + a(n-10) for n > 9.
%F A306753 a(n) = A017877(9*n).
%t A306753 a[n_] := Sum[Binomial[k, 9*(n-k)], {k, 0, n}]; Array[a, 38, 0] (* _Amiram Eldar_, Jun 21 2021 *)
%o A306753 (PARI) {a(n) = sum(k=0, n, binomial(k, 9*(n-k)))}
%o A306753 (PARI) N=66; x='x+O('x^N); Vec((1-x)^8/((1-x)^9-x^10))
%Y A306753 Column 9 of A306680.
%Y A306753 Cf. A017877.
%K A306753 nonn
%O A306753 0,11
%A A306753 _Seiichi Manyama_, Mar 07 2019