OFFSET
4,3
LINKS
Alois P. Heinz, Table of n, a(n) for n = 4..10000
Eric Weisstein's World of Mathematics, Heap
Wikipedia, Binary heap
Index entries for linear recurrences with constant coefficients, signature (1,2,-2,1,-1,-4,4,1,-1,2,-2,-1,1).
FORMULA
G.f.: -x^4*(2*x^3-x^2+1)*(2*x^6-x^5-x^4+x^3+1)/((x^2+1)^2*(x+1)^4*(x-1)^5).
CROSSREFS
KEYWORD
nonn,easy
AUTHOR
Alois P. Heinz, Jul 09 2019
STATUS
approved