A178021 Number of permutations of 3 copies of 1..n with no element e[i>=2]<e[1+floor((i-2)/6)] (6-way heap)

1, 10, 250, 22500, 2788800, 1002405600, 359463283200, 326108342112000, 257963213378304000

Offset

1,2

Links

Table of n, a(n) for n=1..9.

Crossrefs

Simple 2-way heap A056971

Sequence in context: A108792 A265854 A128013 * A134262 A240289 A001536

Adjacent sequences: A178018 A178019 A178020 * A178022 A178023 A178024

Keyword

nonn

Author

R. H. Hardin May 17 2010

Status

approved