A324070 Number of defective (binary) heaps on n elements where nine ancestor-successor pairs do not have the correct order.

0, 0, 0, 0, 0, 0, 0, 240, 4200, 39424, 359520, 3340800, 32630400, 331499520, 3503385600, 38504294400, 386486100000, 4064835174400, 44847772569600, 530121646080000, 6258102529536000, 78618109870080000, 1027628834918400000, 14504975258222592000

Offset

0,8

Comments

Or number of permutations p of [n] having exactly nine pairs (i,j) in {1,...,n} X {1,...,floor(log_2(i))} such that p(i) > p(floor(i/2^j)).

Links

Alois P. Heinz, Table of n, a(n) for n = 0..200

Eric Weisstein's World of Mathematics, Heap

Wikipedia, Binary heap

Wikipedia, Permutation

Crossrefs

Column k=9 of A306393.

Cf. A056971.

Sequence in context: A004536 A234720 A249533 * A145094 A239245 A218131

Adjacent sequences: A324067 A324068 A324069 * A324071 A324072 A324073

Keyword

nonn

Author

Alois P. Heinz, Feb 13 2019

Status

approved