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A013208 Expansion of e.g.f. log(sech(x) + tanh(x)). 1
0, 1, -2, 3, -8, 45, -272, 1743, -13568, 125625, -1290752, 14554683, -181296128, 2473184805, -36501112832, 579439207623, -9859508338688, 179018972217585, -3453141256896512, 70518070842040563 (list; graph; refs; listen; history; text; internal format)
OFFSET

0,3

LINKS

Table of n, a(n) for n=0..19.

EXAMPLE

x - 2/2!*x^2 + 3/3!*x^3 - 8/4!*x^4 + 45/5!*x^5 ...

CROSSREFS

Sequence in context: A042139 A118127 A100644 * A094370 A066084 A141319

Adjacent sequences:  A013205 A013206 A013207 * A013209 A013210 A013211

KEYWORD

sign

AUTHOR

Patrick Demichel (patrick.demichel(AT)hp.com)

EXTENSIONS

a(0)=0 inserted and title improved by Sean A. Irvine, Aug 01 2018

STATUS

approved

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Last modified January 25 07:50 EST 2020. Contains 331241 sequences. (Running on oeis4.)