A063965 Size of the automorphism group of the group S_n x S_n (where S_n is the symmetric group).

1, 6, 72, 1152, 28800, 4147200, 50803200, 3251404800, 263363788800, 26336378880000, 3186701844480000, 458885065605120000, 77551576087265280000, 15200108913103994880000

Offset: 1

Author

Ahmed Fares (ahmedfares(AT)my-deja.com), Sep 04 2001

Keywords

• nonn

Links

• Harry J. Smith, Table of n, a(n) for n = 1..100

Crossrefs

Cf. A060249, A048617.

Programs

Maple

a := proc(n) option remember: if n=1 then RETURN(1) fi: if n=2 then RETURN(6) fi: if n=6 then RETURN(4147200) fi: 2*(n!)^2: end: for n from 1 to 30 do printf(`%d,`,a(n)) od:

PARI

{ for (n=1, 100, if (n==1, a=1, if (n==2, a=6, if (n==6, a=4147200, a=2*(n!)^2))); write("b063965.txt", n, " ", a) ) } \\ Harry J. Smith, Sep 04 2009

Formula

Except for n = 1, 2, and 6, a(n) = A048617(n) = 2*(n!)^2.

Extensions

More terms from James Sellers, Sep 26 2001