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 A384301 #12 May 26 2025 05:20:31
%S A384301 1,6,1680,1235520,1764322560,4151586700800,14572069319808000,
%T A384301 71382386874839040000,465322312113382563840000,
%U A384301 3894941973875807210323968000,40716268141852504209197629440000,519879261146393786614332810854400000,7961721525959456256504412439642112000000
%N A384301 a(n) = Product_{k=0..2*n-1} (3*n+k-1).
%F A384301 a(n) = RisingFactorial(3*n-1,2*n).
%F A384301 a(n) = (2*n)! * [x^(2*n)] 1/(1 - x)^(3*n-1).
%F A384301 a(n) = (2*n)! * binomial(5*n-2,2*n).
%F A384301 D-finite with recurrence 3*(3*n-2)*(3*n-4)*a(n) -5*(5*n-4)*(5*n-3)*(5*n-2)*(5*n-6)*a(n-1)=0. - _R. J. Mathar_, May 26 2025
%o A384301 (PARI) a(n) = (2*n)!*binomial(5*n-2, 2*n);
%Y A384301 Cf. A384300, A384302, A384303.
%Y A384301 Cf. A384263.
%K A384301 nonn,easy
%O A384301 0,2
%A A384301 _Seiichi Manyama_, May 25 2025