OFFSET
1,1
LINKS
MAPLE
with(numtheory): f := z->-1/(1-z-z^2): m := proc(r, j) d := divisors(r): W := (1/r)*z*sum(mobius(d[i])*f(z^d[i])^(r/d[i]), i=1..nops(d)): Wser := simplify(series(W, z=0, 80)): coeff(Wser, z^j) end: seq((-1)^r*m(r, 7), r=1..60);
MATHEMATICA
f[z_] := -1/(1 - z - z^2);
m[r_, j_] := (W = (1/r)*z*Sum[MoebiusMu[d]*f[z^d]^(r/d), {d, Divisors[r]}]; SeriesCoefficient[W, {z, 0, j}]);
Table[(-1)^r*m[r, 7], {r, 1, 40}] (* Jean-François Alcover, Dec 07 2017, from Maple *)
CROSSREFS
KEYWORD
nonn
AUTHOR
N. J. A. Sloane, Dec 05 2003
EXTENSIONS
Edited by Emeric Deutsch, Mar 06 2004
STATUS
approved