A209326 Number of permutations of [n] with a fixed point but no succession.

0, 1, 0, 3, 7, 39, 207, 1437, 11203, 99041, 975645, 10601377, 125905445, 1622349059, 22539777113, 335845307359, 5341990288103, 90340567900583, 1618553943500599, 30623660893656205, 610152486797080443, 12769086757046132625, 280037186109883699885, 6422309829486480886809, 153727262708736577446741, 3833789797689152809143363

Offset

0,4

Comments

A succession of a permutation p is a position i such that p(i+1)-p(i) = 1.

Links

Max Alekseyev, Table of n, a(n) for n = 0..30

Formula

a(n) = A000255(n-1) - A209322(n). - Max Alekseyev, Apr 03 2025

Example

For n=4 we have 1324, 1432, 2431, 3214, 3241, 4132 and 4213.

Crossrefs

Cf. A000166, A000255, A002467, A180191, A207819, A207821, A209322, A209325.

Sequence in context: A057203 A056250 A113870 * A307952 A074582 A105621

Adjacent sequences: A209323 A209324 A209325 * A209327 A209328 A209329

Keyword

nonn

Author

Jon Perry, Jan 19 2013

Extensions

a(11)-a(14) from Alois P. Heinz, Jan 20 2013

a(15)-a(21) from Alois P. Heinz, Jul 04 2021

Terms a(22) onward from Max Alekseyev, Apr 03 2025

Status

approved