OFFSET
0,1
COMMENTS
With the terms indexed as shown, has property that n prime or n=2^k or n=3^k => n divides a(n).
FORMULA
a(n) = x^n+y^n+z^n with e=-1/2+i*sqrt(3)/2, e^2=-1/2-i*sqrt(3)/2, x=((3+sqrt(9-32/27)/2)^(1/3)+((3-sqrt(9-32/27))/2)^(1/3), y=e*((3+sqrt(9-32/27))/2)^(1/3)+(e^2)*((3-sqrt(9-32/27))/2)^(1/3), z=(e^2)*((3+sqrt(9-32/27)/2)^(1/3)+e*((3-sqrt(9-32/27))/2)^(1/3).
G.f.: g(x) = (3-2*x^2)/(1-2*x^2-3*x^3).
CROSSREFS
KEYWORD
easy,nonn
AUTHOR
Miklos Kristof, Jul 15 2002
EXTENSIONS
Corrected by T. D. Noe, Nov 07 2006
More terms from Sean A. Irvine, Sep 23 2024
STATUS
approved