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 A365752 #23 Feb 16 2024 09:53:42 %S A365752 1,3,16,103,735,5592,44452,364815,3067558,26290517,228819168, %T A365752 2016953848,17968790029,161536295244,1463535347928,13349907110367, %U A365752 122499957767130,1130001670577730,10472708110616136,97468774074103041,910582642690819351 %N A365752 Expansion of (1/x) * Series_Reversion( x*(1+x)*(1-x)^4 ). %H A365752 <a href="/index/Res#revert">Index entries for reversions of series</a> %F A365752 a(n) = (1/(n+1)) * Sum_{k=0..n} (-1)^k * binomial(n+k,k) * binomial(5*n-k+3,n-k). %F A365752 a(n) = (1/(n+1)) * Sum_{k=0..floor(n/2)} binomial(n+k,k) * binomial(4*n-2*k+2,n-2*k). - _Seiichi Manyama_, Jan 18 2024 %F A365752 a(n) = (1/(n+1)) * [x^n] 1/( (1+x) * (1-x)^4 )^(n+1). - _Seiichi Manyama_, Feb 16 2024 %o A365752 (PARI) a(n) = sum(k=0, n, (-1)^k*binomial(n+k, k)*binomial(5*n-k+3, n-k))/(n+1); %o A365752 (SageMath) %o A365752 def A365752(n): %o A365752 h = binomial(5*n + 3, n) * hypergeometric([-n, n + 1], [-5 * n - 3], -1) / (n + 1) %o A365752 return simplify(h) %o A365752 print([A365752(n) for n in range(21)]) # _Peter Luschny_, Sep 20 2023 %Y A365752 Cf. A063020, A365751, A365753. %Y A365752 Cf. A365856, A368079. %Y A365752 Cf. A365754, A370105. %K A365752 nonn %O A365752 0,2 %A A365752 _Seiichi Manyama_, Sep 18 2023