A224291 - OEIS

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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

(list; graph; refs; listen; history; text; internal format)

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