OFFSET
1,2
LINKS
FORMULA
a(n) is asymptotic to a*b^n where a = 0.1570450524507584150437292... and b is the real root of: x^3 - 2*x^2 - x - 1; b = 2.546818276884082079135997..
a(n) = 2*a(n-1)+a(n-2)+a(n-3) for n>4. G.f.: x*(3*x^3+2*x^2-1) / (x^3+x^2+2*x-1). - Colin Barker, Jun 24 2013
CROSSREFS
KEYWORD
nonn,easy
AUTHOR
Benoit Cloitre, Nov 22 2002
STATUS
approved