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A009381 Expansion of ln(1+tan(x)/cosh(x)). 0
0, 1, -1, 1, -2, 25, -136, 761, -4752, 42065, -386176, 3898321, -42551552, 521329705, -6816879616, 96017526281, -1446339889152, 23356125062945, -399659935891456, 7240133620964641, -138393644469911552, 2786977252450841785 (list; graph; refs; listen; history; text; internal format)
OFFSET

0,5

LINKS

Table of n, a(n) for n=0..21.

MATHEMATICA

Log[ 1+Tan[ x ]/Cosh[ x ] ]

CROSSREFS

Sequence in context: A226418 A196011 A080515 * A063264 A024533 A220276

Adjacent sequences:  A009378 A009379 A009380 * A009382 A009383 A009384

KEYWORD

sign,easy

AUTHOR

R. H. Hardin

EXTENSIONS

Extended with signs Mar 15 1997 by Olivier Gérard.

STATUS

approved

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Last modified October 2 08:32 EDT 2014. Contains 247538 sequences.