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 A232788 #19 Nov 08 2014 06:58:05
%S A232788 1,1,5,150,6932,965380,143299890,51176650000,16737737386944,
%T A232788 11806879466638656,7023172771916784000,8447153882019234307200,
%U A232788 8134080139379917205277696,15176253254155788712392633600,21875035292051870323313614135440,59270306784445546617788929301760000
%N A232788 A232773(n) / A006882(n): Permanent of the n X n matrix with elements [1,2,...,n^2], divided by n!!.
%C A232788 Limit n->infinity a(n)^(1/n)/n^(5/2) = exp(-3/2). - _Vaclav Kotesovec_, Nov 08 2014
%H A232788 Alois P. Heinz, <a href="/A232788/b232788.txt">Table of n, a(n) for n = 0..100</a>
%p A232788 with(combinat):
%p A232788 a:= n-> (-1)^n *add(n^k *stirling1(n, n-k)*stirling1(n+1, k+1)
%p A232788 *(n-k)!* k!, k=0..n)/doublefactorial(n):
%p A232788 seq(a(n), n=0..20); # _Alois P. Heinz_, Dec 02 2013
%t A232788 Flatten[{1,Table[(-1)^n*Sum[n^k*StirlingS1[n,n-k]*StirlingS1[n+1,k+1]*(n-k)!*k!,{k,0,n}]/n!!,{n,1,20}]}] (* _Vaclav Kotesovec_, Nov 08 2014 *)
%o A232788 (PARI) n->(-1)^n*sum(k=0,n,n^k*stirling(n,n-k)*stirling(n+1,k+1)*(n-k)!*k!)/A006882(n)
%Y A232788 Cf. A232773, A006882.
%K A232788 nonn
%O A232788 0,3
%A A232788 _M. F. Hasler_, Nov 30 2013
%E A232788 a(0)=1 inserted by _Alois P. Heinz_, Dec 02 2013