A086502 - OEIS

A086502

Number of ordered pairs (a,b) of elements of the symmetric group S_n such that the pair a,b generates a proper subgroup of S_n.

%I #5 Feb 21 2013 15:16:35

%S 0,1,18,360,7560,289440,9828000,631169280,46449002880,4526271187200,

%T 524461965350400,74044329341875200,12211524764030592000

%N Number of ordered pairs (a,b) of elements of the symmetric group S_n such that the pair a,b generates a proper subgroup of S_n.

%F a(n) = n!^2 - A071605(n).

%Y Cf. A071605.

%K nonn

%O 1,3

%A Yuval Dekel (dekelyuval(AT)hotmail.com), Sep 09 2003

%E a(10)-(13) from _Stephen A. Silver_, Feb 21 2013