login
A324070
Number of defective (binary) heaps on n elements where nine ancestor-successor pairs do not have the correct order.
2
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
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
KEYWORD
nonn
AUTHOR
Alois P. Heinz, Feb 13 2019
STATUS
approved