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A009808 Expansion of tanh(tan(tan(x))). 0
1, 2, 8, -400, -54016, -6545408, -886739968, -130488590336, -17561155108864, -157860190420992, 1926815267611213824, 1659729586864045162496, 1201487932870410723393536, 858251595734608746586832896 (list; graph; refs; listen; history; text; internal format)
OFFSET

0,2

LINKS

Table of n, a(n) for n=0..13.

MATHEMATICA

Tanh[ Tan[ Tan[ x ] ] ] (* Odd Part *)

CROSSREFS

Sequence in context: A012348 A219994 A014185 * A035129 A003301 A000890

Adjacent sequences:  A009805 A009806 A009807 * A009809 A009810 A009811

KEYWORD

sign

AUTHOR

R. H. Hardin

EXTENSIONS

Extended with signs Mar 15 1997 by Olivier Gerard.

STATUS

approved

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Last modified May 23 14:18 EDT 2013. Contains 225601 sequences.