OFFSET
15,3
FORMULA
G.f.: Sum_{k>=1} mu(k)* x^(15*k) / Product_{j=1..5} (1 - x^(j*k)).
a(n) <= A001401(n-15). - R. J. Mathar, Feb 28 2021
MATHEMATICA
nmax = 70; CoefficientList[Series[Sum[MoebiusMu[k] x^(15 k)/Product[1 - x^(j k), {j, 1, 5}], {k, 1, nmax}], {x, 0, nmax}], x] // Drop[#, 15] &
CROSSREFS
KEYWORD
nonn
AUTHOR
Ilya Gutkovskiy, Feb 23 2021
STATUS
approved