A264321 Number of permutations of [n] with exactly two (possibly overlapping) occurrences of the consecutive pattern 3412.

1, 23, 379, 5706, 84354, 1266150, 19621124, 316459848, 5331647951, 93959680785, 1732274350449, 33392773007922, 672442070185276, 14130089667648160, 309458726679280550, 7054945428667834408, 167218369471952249237, 4115763361988379577315, 105071634182596234984655

Offset

6,2

Links

Alois P. Heinz, Table of n, a(n) for n = 6..200

Example

a(6) = 1: 563412.
a(7) = 23: 1674523, 2674513, 3674512, 4673512, 5614723, 5624713, 5634127, 5634712, 5673412, 5714623, 5724613, 5734126, 5734612, 6573412, 6714523, 6724513, 6734125, 6734512, 6735124, 6745123, 6745132, 6745231, 7563412.

Crossrefs

Column k=2 of A264319.

Sequence in context: A018071 A016325 A016324 * A285234 A046493 A014926

Adjacent sequences: A264318 A264319 A264320 * A264322 A264323 A264324

Keyword

nonn

Author

Alois P. Heinz, Nov 11 2015

Status

approved