OFFSET
1,5
COMMENTS
Reversion of 1 - 1/g(x) where g(x) = g.f. for A005169.
LINKS
N. J. A. Sloane, Transforms
Eric Weisstein's World of Mathematics, Series Reversion
FORMULA
G.f. A(x) satisfies: A(x)/(1 - A(x)^2/(1 - A(x)^3/(1 - A(x)^4/(1 - A(x)^5/(1 - ...))))) = x.
MATHEMATICA
nmax = 38; Rest[CoefficientList[InverseSeries[Series[x/(1 + ContinuedFractionK[-x^k, 1, {k, 2, nmax}]), {x, 0, nmax}], x], x]]
nmax = 38; Rest[CoefficientList[InverseSeries[Series[1 - Sum[(-1)^i x^(i^2)/Product[(1 - x^j), {j, 1, i}], {i, 0, nmax}]/Sum[(-1)^i x^(i (i + 1))/Product[(1 - x^j), {j, 1, i}], {i, 0, nmax}], {x, 0, nmax}], x], x]]
CROSSREFS
KEYWORD
sign
AUTHOR
Ilya Gutkovskiy, Oct 15 2017
STATUS
approved