OFFSET

0,3

COMMENTS

FORMULA

Recurrence: For n >= 4, a(n) = a(n-1)+a(n-d), where d = [3,2,4,2,4,3] according as n == [0,1,2,3,4,5] mod 6; initial conditions a(0)=a(1)=a(2)=1, a(3)=2.

G.f.: (x^17+x^14+x^12+5*x^11+2*x^10-x^9+3*x^8+3*x^7+6*x^5+4*x^4+3*x^3+2*x^2+x+1)/(1-10*x^6-6*x^12-x^18).

a(n) ~ C * D^n, where D = 1.4815692... and C depends on n mod 6 (approximate values of C are [0.580722..., 0.6452899..., 0.554135..., 0.667994..., 0.571395..., 0.556061...], respectively).

CROSSREFS

KEYWORD

nonn,base

AUTHOR

N. J. A. Sloane, Aug 14 2012

STATUS

approved