A178018 Number of permutations of 3 copies of 1..n with no element e[i>=2]<e[1+floor((i-2)/3)] (3-way heap)

1, 5, 94, 4480, 332680, 44019800, 10480204080, 3225666791760, 1530272351292180

Offset

1,2

Links

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

Crossrefs

Simple 2-way heap A056971

Sequence in context: A047052 A049662 A264176 * A195854 A153227 A116159

Adjacent sequences: A178015 A178016 A178017 * A178019 A178020 A178021

Keyword

nonn

Author

R. H. Hardin May 17 2010

Status

approved