A323963 Number of defective (binary) heaps on n elements with exactly seven defects.

0, 210, 7616, 185460, 4200960, 77887920, 1310267904, 21025461600, 314958758400, 4765553385120, 69086614338560, 1013373907056960, 14714554645140480, 212868974122848000, 3168605413206097920, 45787509175434048000, 705241846739554713600, 10297540417675899801600

Offset: 7

Author

Alois P. Heinz, Feb 09 2019

Keywords

• nonn

Comments

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

Links

• Alois P. Heinz, Table of n, a(n) for n = 7..200
• Eric Weisstein's World of Mathematics, Heap
• Wikipedia, Binary heap

Crossrefs

Column k=7 of A306343.

Cf. A056971.