A040173 Numerator of probability that 2 elements of S_n chosen at random (with replacement) generate S_n.

1, 3, 1, 3, 19, 53, 103, 4111, 78293, 29401, 4462987, 9830941, 284397779

Offset

1,2

Links

Table of n, a(n) for n=1..13.

Eric Weisstein's World of Mathematics, Symmetric Group.

Example

Values for n=1,2,3,... are 1, 3/4, 1/2, 3/8, 19/40, 53/120, 103/168, 4111/6720, 78293/120960, ...

Crossrefs

Probability is A040173/A040174 = A040175/n!.

Sequence in context: A361840 A361839 A160708 * A320952 A372816 A128777

Adjacent sequences: A040170 A040171 A040172 * A040174 A040175 A040176

Keyword

nonn,nice,frac,more

Author

Dan Hoey

Extensions

a(10)-a(13) from Stephen A. Silver, Feb 21 2013

Status

approved