OFFSET
-1,1
COMMENTS
Equals b(k) = ((9+sqrt(3))*(3-sqrt(3))^k+(9-sqrt(3))*(3+sqrt(3))^k)/6 for k >= 0. - Klaus Brockhaus, Jul 14 2009
Third binomial transform of A162852.
LINKS
FORMULA
a(n) = 6*a(n-1) - 6*a(n-2) for n > 0; a(-1) = 3, a(0) = 8.
G.f.: (3-10*x)/(x*(1-6*x+6*x^2)).
PROG
(Magma) Z<x>:=PolynomialRing(Integers()); N<r>:=NumberField(x^2-3); S:=[ ((4+r)*(3+r)^n+(4-r)*(3-r)^n): n in [-1..20] ]; [ Integers()!S[j]: j in [1..#S] ]; // Klaus Brockhaus, Jul 14 2009
CROSSREFS
KEYWORD
nonn,easy
AUTHOR
Al Hakanson (hawkuu(AT)gmail.com), Jul 06 2009
EXTENSIONS
Edited and extended beyond a(5)=13608 by Klaus Brockhaus, Jul 18 2009
STATUS
approved