OFFSET
0,2
COMMENTS
Invert transform of A001037.
FORMULA
a(0) = 1; a(n) = Sum_{k=1..n} A001037(k) * a(n-k).
MAPLE
b:= proc(n) option remember; `if`(n=0, 1, (2^n-add(
d*b(d), d=numtheory[divisors](n) minus {n}))/n)
end:
a:= proc(n) option remember; `if`(n=0, 1,
add(a(n-i)*b(i), i=1..n))
end:
seq(a(n), n=0..30); # Alois P. Heinz, Nov 11 2019
MATHEMATICA
nmax = 29; CoefficientList[Series[1/(1 + Sum[MoebiusMu[k] Log[1 - 2 x^k]/k, {k, 1, nmax}]), {x, 0, nmax}], x]
a[0] = 1; a[n_] := a[n] = Sum[(1/k) DivisorSum[k, MoebiusMu[#] 2^(k/#) &] a[n - k], {k, 1, n}]; Table[a[n], {n, 0, 29}]
CROSSREFS
KEYWORD
nonn
AUTHOR
Ilya Gutkovskiy, Nov 11 2019
STATUS
approved