A334854 E.g.f. A(x) satisfies: A(x) = arctan(x * exp(A(x))).

1, 2, 7, 32, 149, 240, -12725, -378880, -8550135, -178474240, -3550577425, -65428992000, -985800819875, -4641229465600, 548638404441075, 36708748623872000, 1716785996161588625, 69798035394846720000, 2571598453132219756375, 84313566554397999104000

Offset: 1

Author

Ilya Gutkovskiy, May 13 2020

Keywords

• sign

Crossrefs

Cf. A227464, A227466.

Programs

Mathematica

nmax = 20; CoefficientList[InverseSeries[Series[Tan[x]/Exp[x], {x, 0, nmax}], x], x] Range[0, nmax]! // Rest

Formula

E.g.f.: series reversion of tan(x) / exp(x).