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 A327417 #8 Mar 24 2020 07:10:27 %S A327417 1,1,682,7128576,429120851544,94066556834970720, %T A327417 57496301859366489159040,82247725949165261902606309120, %U A327417 243263294602173417290925789755652480,1356449073308047884259226117174893156252800,13275987570857688650109290727617026478737341900800 %N A327417 a(n) = A291451(2*n, n). %o A327417 (Sage) # uses[P from A327416] %o A327417 def A327417(n): return P(3, 2*n).list()[n]//factorial(n) %o A327417 print([A327417(n) for n in range(11)]) %Y A327417 Cf. A007820 (m=1), A327416 (m=2), this sequence (m=3), A327418 (m=4). %Y A327417 Associated triangles: A048993 (m=1), A156289 (m=2), A291451 (m=3), A291452 (m=4). %K A327417 nonn %O A327417 0,3 %A A327417 _Peter Luschny_, Sep 14 2019