The OEIS mourns the passing of Jim Simons and is grateful to the Simons Foundation for its support of research in many branches of science, including the OEIS.
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!)
A024257 Expansion of tanh(tan(x)*x)/2. 1
0, 1, 4, -72, -5632, -161920, 18173952, 4194147328, 310213328896, -84365860995072, -39813939519815680, -5549928926785306624, 2813587774502929956864, 2234702652489178135134208, 497733049858403607865458688 (list; graph; refs; listen; history; text; internal format)
OFFSET
0,3
LINKS
MATHEMATICA
With[{nn=30}, Take[CoefficientList[Series[Tanh[Tan[x]*x]/2 , {x, 0, nn}], x] Range[0, nn]!, {1, -1, 2}]] (* Harvey P. Dale, Apr 27 2016 *)
CROSSREFS
Cf. A009817.
Sequence in context: A076744 A177392 A158269 * A152653 A344693 A172478
KEYWORD
sign
AUTHOR
EXTENSIONS
Extended with signs Mar 1997
Prior Mathematica program deleted by Harvey P. Dale, Apr 27 2016
STATUS
approved

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 June 16 05:29 EDT 2024. Contains 373423 sequences. (Running on oeis4.)