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A009376 Expansion of log(1 + tan(x)*exp(x)). 0
0, 1, 1, 1, -2, 5, 6, 131, -552, 3065, -10934, 216511, -1516052, 13359125, -110965074, 1704426491, -17363056752, 210045171185, -2585510594414, 41595973502071, -563643499480652, 8626434032607245, -136389526384050954 (list; graph; refs; listen; history; text; internal format)
OFFSET

0,5

LINKS

Table of n, a(n) for n=0..22.

FORMULA

a(n) ~ (n-1)! * (-1)^(n+1) / r^n, where r = 1.306326940423079236174356658440682315179068358... is the root of the equation tan(r)/exp(r) = 1. - Vaclav Kotesovec, Jan 24 2015

MATHEMATICA

Log[ 1+Tan[ x ]*Exp[ x ] ]

CoefficientList[Series[Log[1 + E^x*Tan[x]], {x, 0, 20}], x] * Range[0, 20]! (* Vaclav Kotesovec, Jan 24 2015 *)

CROSSREFS

Sequence in context: A111190 A244434 A176007 * A231364 A025123 A071791

Adjacent sequences:  A009373 A009374 A009375 * A009377 A009378 A009379

KEYWORD

sign,easy

AUTHOR

R. H. Hardin

EXTENSIONS

Extended with signs by Olivier Gérard, Mar 15 1997

STATUS

approved

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Last modified November 27 03:56 EST 2021. Contains 349345 sequences. (Running on oeis4.)