A179263 Number of permutations of 1..n with sum (i-p(i))^2 <= n*(n-1)/2.

1, 1, 3, 9, 27, 87, 350, 1675, 7848, 36711, 196510, 1177139, 6908609, 40106433, 256572630, 1785661795, 12221831460, 82732094377, 603846490132, 4714585241090, 36290179829390, 276421527541533

Offset

1,3

Links

Table of n, a(n) for n=1..22.

Crossrefs

Sequence in context: A176826 A146786 A151029 * A147242 A148924 A113994

Adjacent sequences: A179260 A179261 A179262 * A179264 A179265 A179266

Keyword

nonn

Author

R. H. Hardin, Jul 06 2010

Status

approved