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A012756 exp(arctanh(x)*arctanh(x))=1+2/2!*x^2+28/4!*x^4+968/6!*x^6+61584/8!*x^8... 1
1, 2, 28, 968, 61584, 6221472, 912779712, 183144253056, 48126940270848, 16031131073204736, 6598147635721116672, 3287285755024478177280, 1949289186179973455646720, 1356446896562442205265633280 (list; graph; refs; listen; history; text; internal format)
OFFSET

0,2

LINKS

Vaclav Kotesovec, Table of n, a(n) for n = 0..223

MATHEMATICA

nn = 20; Table[(CoefficientList[Series[E^(ArcTanh[x]^2), {x, 0, 2*nn}], x] * Range[0, 2*nn]!)[[n]], {n, 1, 2*nn+1, 2}] (* Vaclav Kotesovec, Feb 08 2015 *)

CROSSREFS

Sequence in context: A009256 A012725 A264637 * A009403 A026944 A296464

Adjacent sequences:  A012753 A012754 A012755 * A012757 A012758 A012759

KEYWORD

nonn

AUTHOR

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

STATUS

approved

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Last modified December 11 12:33 EST 2019. Contains 329916 sequences. (Running on oeis4.)