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 A110144 #3 Mar 30 2012 18:36:49 %S A110144 1,2,3,8,6,48,24,384,144,3840,1152,46080,11520,645120,138240,10321920, %T A110144 1935360,185794560,30965760,3715891200,557383680,81749606400, %U A110144 11147673600,1961990553600,245248819200,51011754393600,5885971660800 %N A110144 Terms of A110142 at positions p(n)+1, where p(n) = A000041(n) is the number of partitions of n; a(n) = A110142(p(n)+1) for n>=1, with a(0) = 1. %F A110144 a(2*n+1) = 2^n*n!, a(2*n+2) = 3*2^n*n! for n>0, with a(0) = 1. %o A110144 (PARI) a(n)=if(n==0,1,if(n%2==1,2^(n\2+1)*(n\2+1)!,3*2^((n-1)\2)*((n-1)\2)!)) %Y A110144 Cf. A110142, A110141, A000041, A000165 (double factorials). %K A110144 nonn %O A110144 0,2 %A A110144 _Paul D. Hanna_, Jul 14 2005