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

Author

Alois P. Heinz, Feb 13 2019

Keywords

• nonn

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.