The OEIS Foundation is supported by donations from users of the OEIS and by a grant from the Simons 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 56th year, we are closing in on 350,000 sequences, and we’ve crossed 9,700 citations (which often say “discovered thanks to the OEIS”).

 Hints (Greetings from The On-Line Encyclopedia of Integer Sequences!)
 A013184 exp(arctanh(x)+tanh(x)) = 1+2*x+4/2!*x^2+8/3!*x^3+16/4!*x^4+72/5!*x^5... 0
 1, 2, 4, 8, 16, 72, 544, 3936, 25344, 193920, 1920384, 21876736, 246359040, 2967878656, 39508168704, 589063146496, 9120978370560, 149737853943808, 2587275558617088, 48291040167362560, 939278027083448320 (list; graph; refs; listen; history; text; internal format)
 OFFSET 0,2 LINKS FORMULA a(n) ~ 2*exp(tanh(1)) * n^n/exp(n) = 2*exp((exp(2)-1)/(exp(2)+1)) * n^n/exp(n). - Vaclav Kotesovec, Oct 24 2013 MATHEMATICA With[{nn=20}, CoefficientList[Series[Exp[ArcTanh[x]+Tanh[x]], {x, 0, nn}], x] Range[0, nn]!] (* Harvey P. Dale, Jul 24 2011 *) CROSSREFS Sequence in context: A322037 A013133 A012997 * A066713 A004000 A051300 Adjacent sequences:  A013181 A013182 A013183 * A013185 A013186 A013187 KEYWORD nonn AUTHOR Patrick Demichel (patrick.demichel(AT)hp.com) STATUS approved

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

Last modified December 1 13:38 EST 2021. Contains 349429 sequences. (Running on oeis4.)