

A014767


Order of shuffle group on n cards {0..n1} generated by i>n1i and i>min{2i,2n12i}.


0



1, 2, 6, 12, 60, 120, 5040, 32, 181440, 3628800, 39916800, 95040, 3113510400, 87178291200, 1307674368000, 80, 177843714048000, 6402373705728000, 121645100408832000, 1216451004088320000, 25545471085854720000
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OFFSET

1,2


REFERENCES

J. H. Conway and N. J. A. Sloane, "Sphere Packings, Lattices and Groups", SpringerVerlag, p. 323.


LINKS

Table of n, a(n) for n=1..21.


PROG

(MAGMA) S := function(n) G := Sym({0..n1}); p := &*[ G  (i, n1i) : i in [ 0..Floor((n2)/2) ] ];
q := G![ Min(2*i, 2*n12*i):i in [ 0..n1 ] ]; return Order(sub<G  p, q >); end function;


CROSSREFS

Sequence in context: A138570 A161887 A139315 * A002319 A195307 A101657
Adjacent sequences: A014764 A014765 A014766 * A014768 A014769 A014770


KEYWORD

nonn,easy,nice


AUTHOR

N. J. A. Sloane.


STATUS

approved



