A152501 1/8 the number of permutations of 3 indistinguishable copies of 1..n with exactly 4 local maxima.

0, 0, 46, 22615, 5036741, 819235874, 114962084772, 14974498962192, 1876234090571968, 230313563301166336, 27966954502164518912, 3376705184454377873408, 406486565581361073979392, 48857132166440216820449280, 5867654791849010140880306176, 704409107074292841154786361344

Offset

1,3

Links

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

Prog

(PARI) \\ PeaksBySig defined in A334774.
a(n) = {PeaksBySig(vector(n, i, 3), [3])[1]/8} \\ Andrew Howroyd, May 12 2020

Crossrefs

Cf. A152499, A334774.

Sequence in context: A134793 A177639 A222097 * A209474 A336439 A159406

Adjacent sequences: A152498 A152499 A152500 * A152502 A152503 A152504

Keyword

nonn

Author

R. H. Hardin, Dec 06 2008

Extensions

Terms a(9) and beyond from Andrew Howroyd, May 12 2020

Status

approved