login
a(n) = (n!)!/n!.
0

%I #23 Dec 29 2022 12:09:15

%S 1,1,1,120,25852016738884976640000

%N a(n) = (n!)!/n!.

%C The next two terms have 197 and 1744 decimal digits, respectively.

%C a(n) gives the number of different ways in which a table of permutations for n objects can be arranged when one of them is fixed at the same place. Also: some of the first terms in this sequence belong to A010050. - _R. J. Cano_, Jan 23 2013

%H <a href="/index/Di#divseq">Index to divisibility sequences</a>

%H <a href="/index/Fa#factorial">Index entries for sequences related to factorial numbers</a>

%F a(n) = (n!-1)!.

%F a(n) = A000197(n)/n!.

%o (PARI) a(n)=(n!-1)! \\ _R. J. Cano_, Jan 23 2013

%Y Cf. A000142, A000197, A010050.

%K nonn,easy

%O 0,4

%A Ken Alverson (KenA(AT)tso.cin.ix.ne)

%E Corrections made by _Eric M. Schmidt_, Jan 23 2013