A326507 Number of (binary) max-heaps on n elements from the set {0,1} containing exactly six 0's.

1, 1, 2, 5, 9, 16, 27, 44, 68, 114, 156, 236, 325, 500, 622, 900, 1143, 1659, 1954, 2731, 3277, 4564, 5185, 7040, 8114, 10948, 12124, 16058, 17977, 23640, 25692, 33304, 36493, 46965, 50322, 64017, 69025, 87208, 92423, 115652, 123168, 153142, 160908, 198440

Offset

6,3

Links

Alois P. Heinz, Table of n, a(n) for n = 6..10000

Eric Weisstein's World of Mathematics, Heap

Wikipedia, Binary heap

Index entries for linear recurrences with constant coefficients, signature (1, 2, -2, 3, -3, -8, 8, -2, 2, 12, -12, -2, 2, -8, 8, 3, -3, 2, -2, -1, 1).

Formula

G.f. x^6*(1 -x^2 +3*x^3 +x^5 -6*x^7 +15*x^9 -17*x^10 -x^11 +19*x^12 -9*x^13 -6*x^14 +12*x^15 +x^17 -x^4 +8*x^6 -3*x^16) / ( (x^2+1)^4 *(1+x)^6 *(1-x)^7 ). - R. J. Mathar, May 06 2026

Mathematica

LinearRecurrence[{1, 2, -2, 3, -3, -8, 8, -2, 2, 12, -12, -2, 2, -8, 8, 3, -3, 2, -2, -1, 1}, {1, 1, 2, 5, 9, 16, 27, 44, 68, 114, 156, 236, 325, 500, 622, 900, 1143, 1659, 1954, 2731, 3277}, 50] (* Ray Chandler, Sep 25 2022 *)

Crossrefs

Column k=6 of A309049.

Sequence in context: A225596 A211881 A056870 * A014739 A290464 A335768

Adjacent sequences: A326504 A326505 A326506 * A326508 A326509 A326510

Keyword

nonn,easy

Author

Alois P. Heinz, Jul 09 2019

Status

approved