A326504 Number of (binary) max-heaps on n elements from the set {0,1} containing exactly three 0's.

1, 1, 2, 4, 6, 8, 12, 16, 23, 27, 38, 44, 60, 66, 88, 96, 125, 133, 170, 180, 226, 236, 292, 304, 371, 383, 462, 476, 568, 582, 688, 704, 825, 841, 978, 996, 1150, 1168, 1340, 1360, 1551, 1571, 1782, 1804, 2036, 2058, 2312, 2336, 2613, 2637, 2938, 2964, 3290

Offset

3,3

Links

Alois P. Heinz, Table of n, a(n) for n = 3..10000

Eric Weisstein's World of Mathematics, Heap

Wikipedia, Binary heap

Index entries for linear recurrences with constant coefficients, signature (1,2,-2,0,0,-2,2,1,-1).

Formula

G.f.: x^3*(2*x^6-2*x^5+2*x^3-x^2+1)/((x^2+1)*(x+1)^3*(x-1)^4).

Mathematica

LinearRecurrence[{1, 2, -2, 0, 0, -2, 2, 1, -1}, {1, 1, 2, 4, 6, 8, 12, 16, 23}, 60] (* Harvey P. Dale, Mar 11 2023 *)

Crossrefs

Column k=3 of A309049.

Sequence in context: A228354 A065386 A048951 * A058629 A323508 A324850

Adjacent sequences: A326501 A326502 A326503 * A326505 A326506 A326507

Keyword

nonn,easy

Author

Alois P. Heinz, Jul 09 2019

Status

approved