A178022 Number of permutations of 4 copies of 1..n with no element e[i>=2]<e[1+floor((i-2)/2)] (2-way heap).

1, 7, 206, 18155, 3340366, 1345907216, 965180428296, 1192995518065240

Offset

1,2

Links

Table of n, a(n) for n=1..8.

Crossrefs

Simple 2-way heap A056971

Sequence in context: A234619 A308614 A393857 * A157775 A300619 A385526

Adjacent sequences: A178019 A178020 A178021 * A178023 A178024 A178025

Keyword

nonn

Author

R. H. Hardin, May 17 2010

Status

approved