A009169 - OEIS

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A009169

Expansion of cosh(tanh(log(1+x))).

1, 0, 1, -3, 4, 20, -224, 1344, -5144, -4320, 356896, -4755520, 42368536, -207434448, -1593929336, 61487349000, -997231605824, 9976381236224, -16539522000704, -1929601048449600, 51992648244966016, -800205465246136320

(list; graph; refs; listen; history; text; internal format)

OFFSET

0,4

LINKS

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

MATHEMATICA

Cosh[ Tanh[ Log[ 1+x ] ] ]

CROSSREFS

Sequence in context: A326424 A151357 A250105 * A265710 A322673 A306650

Adjacent sequences: A009166 A009167 A009168 * A009170 A009171 A009172

KEYWORD

sign,easy

AUTHOR

R. H. Hardin

EXTENSIONS

Extended with signs by Olivier Gérard, Mar 15 1997

STATUS

approved