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
KEYWORD
nonn,easy
AUTHOR
Alois P. Heinz, Jul 09 2019
STATUS
approved