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 A216629 #7 Feb 03 2025 13:51:59 %S A216629 1,1,2,12,18,540,1200,168000,735000,463050000,4667544000, %T A216629 12938431968000,332086420512000,3989022083190144000, %U A216629 279394363051195392000,14383221809875538780160000,2892376010829659126572800000,632822947409421120302862912000000 %N A216629 a(n) = A163085(n)/(floor(n/2)!)^2. %o A216629 (Sage) %o A216629 def A216629(n): return A163085(n)/factorial(n//2)^2 %o A216629 [A216629(n) for n in (0..17)] %Y A216629 Cf. A069651. %K A216629 nonn %O A216629 0,3 %A A216629 _Peter Luschny_, Sep 18 2012