login

Year-end appeal: Please make a donation to the OEIS Foundation to support ongoing development and maintenance of the OEIS. We are now in our 61st year, we have over 378,000 sequences, and we’ve reached 11,000 citations (which often say “discovered thanks to the OEIS”).

A323966
Number of defective (binary) heaps on n elements with exactly ten defects.
2
0, 19200, 947760, 49680576, 1744142400, 60169824000, 1646888944800, 42633973724160, 1013373907056960, 22797317814635520, 502986050203680000, 10556482426015426560, 222685725334400064000, 4535040919258899456000, 92995172484979478630400, 1880492299058130490163200
OFFSET
10,2
COMMENTS
Or number of permutations p of [n] having exactly ten indices i in {1,...,n} such that p(i) > p(floor(i/2)).
LINKS
Eric Weisstein's World of Mathematics, Heap
Wikipedia, Binary heap
CROSSREFS
Column k=10 of A306343.
Cf. A056971.
Sequence in context: A249106 A184196 A210316 * A035925 A186875 A251803
KEYWORD
nonn
AUTHOR
Alois P. Heinz, Feb 09 2019
STATUS
approved