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A009369 Expansion of log(1+tan(x))*cos(x). 0
0, 1, -1, 1, -8, 45, -301, 2357, -21608, 223769, -2602081, 33484713, -473210528, 7282225093, -121272163741, 2172791685469, -41680241726768, 852337358029617, -18510436676621281, 425474580069715025, -10319766893265298328 (list; graph; refs; listen; history; text; internal format)
OFFSET

0,5

LINKS

Table of n, a(n) for n=0..20.

FORMULA

a(n) ~ (n-1)! * (-1)^(n+1) * 2^(2*n-1/2) / Pi^n. - Vaclav Kotesovec, Jan 23 2015

MATHEMATICA

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

CoefficientList[Series[Cos[x]*Log[1 + Tan[x]], {x, 0, 20}], x] * Range[0, 20]! (* Vaclav Kotesovec, Jan 23 2015 *)

CROSSREFS

Sequence in context: A204618 A289896 A006887 * A120044 A002686 A110348

Adjacent sequences:  A009366 A009367 A009368 * A009370 A009371 A009372

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 September 26 14:12 EDT 2017. Contains 292529 sequences.