A014525 Order of shuffle group for deck of 3n cards.

1, 6, 720, 72, 239500800, 1307674368000, 6402373705728000, 51090942171709440000, 310224200866619719680000, 648, 265252859812191058636308480000000

Offset

0,2

References

W. Bosma et al., Solving Problems with Magma, Sect. 2.2.3.

Cannon and Playoust, An Introduction to MAGMA, Section 6.3.1.

Links

Sean A. Irvine, Table of n, a(n) for n = 0..33

Formula

Conjecture: a(3^m) = (m+1) * 6^(m+1), a(4*m) = (1/2) * (3*4*m)!, otherwise a(n) = (3*n)!. - Sean A. Irvine, Nov 07 2018

Prog

(Magma) SG := function(n) m := 3*n; G := SymmetricGroup(m); p := &*[ G | (i, i+2*n): i in [ 1..n ]]; q := &*[ G | (i, i+n, i+2*n): i in [ 1..n ]]; s := [ ((i-1) mod 3 ) * n + (i-1) div 3 + 1: i in [ 1..m ]]; return Order(sub<G | p, q, s >); end function;

Crossrefs

Cf. A014766.

Sequence in context: A201391 A374331 A289367 * A289747 A188960 A100732

Adjacent sequences: A014522 A014523 A014524 * A014526 A014527 A014528

Keyword

nonn

Author

N. J. A. Sloane

Status

approved