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

 

Logo
Hints
(Greetings from The On-Line Encyclopedia of Integer Sequences!)
A012756 exp(arctanh(x)*arctanh(x))=1+2/2!*x^2+28/4!*x^4+968/6!*x^6+61584/8!*x^8... 1

%I #8 Feb 08 2015 07:34:54

%S 1,2,28,968,61584,6221472,912779712,183144253056,48126940270848,

%T 16031131073204736,6598147635721116672,3287285755024478177280,

%U 1949289186179973455646720,1356446896562442205265633280

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

%H Vaclav Kotesovec, <a href="/A012756/b012756.txt">Table of n, a(n) for n = 0..223</a>

%t 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 *)

%K nonn

%O 0,2

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

Lookup | Welcome | Wiki | Register | Music | Plot 2 | Demos | Index | Browse | More | WebCam
Contribute new seq. or comment | Format | Style Sheet | Transforms | Superseeker | Recents
The OEIS Community | Maintained by The OEIS Foundation Inc.

License Agreements, Terms of Use, Privacy Policy. .

Last modified April 23 18:16 EDT 2024. Contains 371916 sequences. (Running on oeis4.)