A180894 Number of permutations of 6..n+5 with no element greater than or equal to the sum of its neighbors.

1, 0, 2, 6, 30, 180, 1260, 9720, 83100, 765456, 7666722, 82008890, 943538544, 11524375162, 150143430468, 2065180190206, 30086424947400, 460533014625124

Offset

1,3

Links

Table of n, a(n) for n=1..18.

Crossrefs

Sequence in context: A290354 A293906 A180893 * A180895 A180896 A180897

Adjacent sequences: A180891 A180892 A180893 * A180895 A180896 A180897

Keyword

nonn

Author

R. H. Hardin, Sep 23 2010

Status

approved