OFFSET
1,4
LINKS
Eric Weisstein's World of Mathematics, Graph Thickness
FORMULA
G.f.: x(1+x^3-x^4)/((1-x)^2(1+x)(1+x^2)). - R. J. Mathar, Sep 12 2008
MATHEMATICA
Ceiling[(n+1)/4]
CROSSREFS
KEYWORD
dead
AUTHOR
Eric W. Weisstein, Sep 09 2008
STATUS
approved