A183265 Number of singly defective permutations of 1..n+2 with exactly 2 maxima.

3, 80, 860, 6576, 42112, 242688, 1306944, 6721280, 33448448, 162435072, 774052864, 3633229824, 16842670080, 77264322560, 351273107456, 1584582819840, 7098965819392, 31609517506560, 139978221551616, 616818283642880, 2705880365662208, 11821908555202560, 51457052429516800

Offset

1,1

Comments

A singly defective permutation omits one value and repeats another value.

Links

Andrew Howroyd, Table of n, a(n) for n = 1..200

Example

Some solutions for n=3 with 2 maxima:
(1,4,2,3,2) (3,5,1,4,5) (4,1,2,5,2) (3,2,2,4,1) (2,1,4,5,2) (4,4,3,1,2).

Crossrefs

Column 2 of A183270.

Sequence in context: A011187 A327250 A197248 * A233124 A251694 A355626

Adjacent sequences: A183262 A183263 A183264 * A183266 A183267 A183268

Keyword

nonn

Author

R. H. Hardin, Jan 03 2011

Extensions

Terms a(14) and beyond from Andrew Howroyd, May 12 2020

Status

approved