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 A371495 #8 Mar 25 2024 09:21:31
%S A371495 1,3,12,64,381,2430,16227,112008,792717,5721165,41945373,311529831,
%T A371495 2338909219,17722127580,135346614906,1040779011412,8051611785006,
%U A371495 62620659604659,489339248275242,3840135625895886,30251386980891657,239138782521553659,1896380840948325606
%N A371495 G.f. A(x) satisfies A(x) = 1 / (1 - x*A(x) / (1+x))^3.
%F A371495 a(n) = Sum_{k=0..n} (-1)^(n-k) * binomial(n-1,n-k) * binomial(4*k+2,k)/(k+1).
%o A371495 (PARI) a(n) = sum(k=0, n, (-1)^(n-k)*binomial(n-1, n-k)*binomial(4*k+2, k)/(k+1));
%Y A371495 Cf. A001006, A371494, A371496.
%Y A371495 Cf. A006632.
%K A371495 nonn
%O A371495 0,2
%A A371495 _Seiichi Manyama_, Mar 25 2024