A323965 Number of defective (binary) heaps on n elements with exactly nine defects.

0, 3360, 190800, 6837600, 239978112, 6268548000, 153775564800, 3365570435040, 69086614338560, 1386261729792960, 26344715667079680, 502986050203680000, 9251596509192069120, 171657357483560256000, 3142069546022259916800, 57414248711716723200000

Offset: 9

Author

Alois P. Heinz, Feb 09 2019

Keywords

• nonn

Comments

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

Links

• Alois P. Heinz, Table of n, a(n) for n = 9..200
• Eric Weisstein's World of Mathematics, Heap
• Wikipedia, Binary heap

Crossrefs

Column k=9 of A306343.

Cf. A056971.