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A014525
Order of shuffle group for deck of 3n cards.
2
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
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
KEYWORD
nonn
STATUS
approved