A189508 Column 2 of triangle in A189507.

1, 3, 21, 160, 1620, 19068, 264420, 4166880, 74011488, 1459381440, 31674232128

Offset

1,2

Links

Table of n, a(n) for n=1..11.

Simona Grusea and Anthony Labarre, The distribution of cycles in breakpoint graphs of signed permutations, arXiv:1104.3353 [cs.DM], 2011-2012.

Crossrefs

Cf. A189507.

Sequence in context: A372463 A358953 A382920 * A074570 A136781 A225439

Adjacent sequences: A189505 A189506 A189507 * A189509 A189510 A189511

Keyword

nonn,more

Author

N. J. A. Sloane, Apr 23 2011

Extensions

Missing term for n=9 added by Anthony Labarre, Feb 14 2013

Status

approved