OFFSET
0,3
COMMENTS
a(53) is negative. - Vaclav Kotesovec, Jan 26 2020
LINKS
Vaclav Kotesovec, Table of n, a(n) for n = 0..400
FORMULA
a(0) = 1; a(n) = Sum_{k=1..n} binomial(n-1,k-1) * A191700(k) * a(n-k).
MATHEMATICA
nmax = 21; CoefficientList[Series[Exp[1/(1 - ArcTan[x]) - 1], {x, 0, nmax}], x] Range[0, nmax]!
PROG
(PARI) seq(n)={Vec(serlaplace(exp(1/(1 - atan(x + O(x*x^n))) - 1)))} \\ Andrew Howroyd, Jan 22 2020
CROSSREFS
KEYWORD
sign
AUTHOR
Ilya Gutkovskiy, Jan 22 2020
STATUS
approved