OFFSET
1,2
COMMENTS
Reversion of g.f. for A001615 (Dedekind psi function).
LINKS
N. J. A. Sloane, Transforms
Eric Weisstein's World of Mathematics, Series Reversion
Eric Weisstein's World of Mathematics, Dedekind Function
FORMULA
G.f. A(x) satisfies: Sum_{k>=1} A(x)^k*k*Product_{p|k, p prime} (1 + 1/p) = x.
CROSSREFS
KEYWORD
sign
AUTHOR
Ilya Gutkovskiy, Sep 25 2017
STATUS
approved