The On-Line Encyclopedia of Integer Sequences (OEIS)

The OEIS is supported by the many generous donors to the OEIS Foundation.

Year-end appeal: Please make a donation to the OEIS Foundation to support ongoing development and maintenance of the OEIS. We are now in our 61st year, we have over 378,000 sequences, and we’ve reached 11,000 citations (which often say “discovered thanks to the OEIS”).

Other ways to Give

A012756 revision #5

A012756

exp(arctanh(x)*atanh(x))=1+2/2!*x^2+28/4!*x^4+968/6!*x^6+61584/8!*x^8...

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

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

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: A012725 A264637 A352251 * A362587 A009403 A026944

Adjacent sequences: A012753 A012754 A012755 * A012757 A012758 A012759

KEYWORD

nonn

AUTHOR

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

STATUS

editing