A180881 Number of permutations p() of 1..n+4 with centered difference p(i+1)-p(i-1) < 0 exactly 3 times.

10, 160, 1960, 17080, 130914, 877968, 5517204, 32369568, 183346020, 997586304, 5324138820, 27695982600, 142629565650, 721661798000, 3635721869780, 18075459889344, 89830487207916, 441561520370880, 2175990796288400

Offset

1,1

Links

R. H. Hardin, Table of n, a(n) for n=1..100

Prog

(bc) /* See A180887 */

Crossrefs

Column 4 of A180887.

Sequence in context: A360935 A116041 A284110 * A106261 A386897 A112125

Adjacent sequences: A180878 A180879 A180880 * A180882 A180883 A180884

Keyword

nonn

Author

R. H. Hardin, Sep 23 2010

Status

approved