A323962 Number of defective (binary) heaps on n elements with exactly six defects.

0, 80, 1526, 34160, 576060, 8762880, 123760560, 1602344832, 21025461600, 264121228800, 3365570435040, 42633973724160, 535972460752320, 7005009151595520, 88526770797830400, 1212423433054986240, 15530632515845568000, 223695310100356300800, 2930160761881213132800

Offset: 6

Author

Alois P. Heinz, Feb 09 2019

Keywords

• nonn

Comments

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

Links

• Alois P. Heinz, Table of n, a(n) for n = 6..200
• Eric Weisstein's World of Mathematics, Heap
• Wikipedia, Binary heap

Crossrefs

Column k=6 of A306343.

Cf. A056971.