A180394 Number of permutations of 1..n with both permutation and its inverse having exactly 4 maxima

0, 0, 0, 0, 0, 0, 19, 1784, 55092, 952640, 11346508, 103655440, 774656344, 4940080352, 27682462431

Offset

1,7

Links

Table of n, a(n) for n=1..15.

Crossrefs

Sequence in context: A242564 A068748 A289736 * A220990 A098846 A116012

Adjacent sequences: A180391 A180392 A180393 * A180395 A180396 A180397

Keyword

nonn

Author

R. H. Hardin Sep 01 2010

Status

approved