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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.
0
0, 1, 18, 360, 7560, 289440, 9828000, 631169280, 46449002880, 4526271187200, 524461965350400, 74044329341875200, 12211524764030592000
OFFSET
1,3
FORMULA
a(n) = n!^2 - A071605(n).
CROSSREFS
Cf. A071605.
Sequence in context: A366684 A182609 A320764 * A259459 A099276 A221348
KEYWORD
nonn
AUTHOR
Yuval Dekel (dekelyuval(AT)hotmail.com), Sep 09 2003
EXTENSIONS
a(10)-(13) from Stephen A. Silver, Feb 21 2013
STATUS
approved