OFFSET
0,1
FORMULA
a_n is the union of {3, 6}; the numbers {v_n} where v_0 = 5, v_n=3*v_{n-1}+2; and the numbers u_n = 2 + v_n.
Conjectures from Colin Barker, Sep 09 2017: (Start)
G.f.: (3 + 8*x + 2*x^2 - 11*x^3 - 9*x^4 - 3*x^5) / ((1 + x)*(1 - 3*x^2)).
a(n) = -(-1)^n + 3^((n-1)/2)*(1-(-1)^n + sqrt(3) + (-1)^n*sqrt(3)) for n>2.
a(n) = -a(n-1) + 3*a(n-2) + 3*a(n-3) for n>5.
(End)
EXAMPLE
4 is not in the sequence because it is in A000079.
14 is not in the sequence because 14 = 3+5+6.
CROSSREFS
KEYWORD
nonn
AUTHOR
Floor van Lamoen, Jun 26 2002
STATUS
approved