A224291 Number of permutations of length n containing exactly 4 occurrences of 123 and 4 occurrences of 132.

0, 0, 0, 0, 1, 11, 60, 270, 1084, 4028, 14144, 47577, 154740, 489728, 1514786, 4593118, 13682374, 40106060, 115824376, 329901232, 927585696, 2576685888, 7076644480, 19228648192, 51725149184

Offset

1,6

Links

Table of n, a(n) for n=1..25.

B. Nakamura, Approaches for enumerating permutations with a prescribed number of occurrences of patterns, arXiv 1301.5080, 2013.

Maple

# Programs can be obtained from author's personal website.

Crossrefs

Cf. A000079, A001787, A001815, A046718, A001793.

Sequence in context: A044530 A050483 A066999 * A055826 A324622 A156704

Adjacent sequences: A224288 A224289 A224290 * A224292 A224293 A224294

Keyword

nonn

Author

Brian Nakamura, Apr 03 2013

Status

approved