A323964 Number of defective (binary) heaps on n elements with exactly eight defects.

0, 896, 32460, 1201920, 29987760, 705522048, 14197154400, 264121228800, 4765553385120, 80958196300800, 1386261729792960, 22797317814635520, 378396940680172800, 6210934579834490880, 101592763596409536000, 1694705349980956262400, 27653450672540750745600

Offset

8,2

Comments

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

Links

Alois P. Heinz, Table of n, a(n) for n = 8..200

Eric Weisstein's World of Mathematics, Heap

Wikipedia, Binary heap

Crossrefs

Column k=8 of A306343.

Cf. A056971.

Sequence in context: A218814 A264329 A287944 * A145498 A252378 A210129

Adjacent sequences: A323961 A323962 A323963 * A323965 A323966 A323967

Keyword

nonn

Author

Alois P. Heinz, Feb 09 2019

Status

approved