OFFSET
0,3
COMMENTS
Invert transform of A001511.
FORMULA
G.f.: 1 / (1 - Sum_{k>=0} x^(2^k) / (1 - x^(2^k))).
a(0) = 1; a(n) = Sum_{k=1..n} A001511(k) * a(n-k).
MATHEMATICA
nmax = 32; CoefficientList[Series[1/(1 - Sum[x^(2^k)/(1 - x^(2^k)), {k, 0, Floor[Log[2, nmax]] + 1}]), {x, 0, nmax}], x]
a[0] = 1; a[n_] := a[n] = Sum[IntegerExponent[2 k, 2] a[n - k], {k, 1, n}]; Table[a[n], {n, 0, 32}]
CROSSREFS
KEYWORD
nonn
AUTHOR
Ilya Gutkovskiy, Sep 23 2019
STATUS
approved