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!)
A012133 sech(arcsin(tanh(x)))=1-1/2!*x^2+9/4!*x^4-201/6!*x^6+8369/8!*x^8... 0
1, -1, 9, -201, 8369, -559601, 54852729, -7411089401, 1320161221089, -299803443573601, 84543945702681449, -28984920596097196201, 11872728882101557841809, -5726623333843769342341201 (list; graph; refs; listen; history; text; internal format)
OFFSET
0,3
LINKS
MATHEMATICA
With[{nn=30}, Take[CoefficientList[Series[Sech[ArcSin[Tanh[x]]], {x, 0, nn}], x] Range[ 0, nn]!, {1, -1, 2}]] (* Harvey P. Dale, Sep 21 2022 *)
CROSSREFS
Sequence in context: A052145 A012061 A012168 * A012038 A012108 A251587
KEYWORD
sign
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 | Recents
The OEIS Community | Maintained by The OEIS Foundation Inc.

License Agreements, Terms of Use, Privacy Policy. .

Last modified February 24 17:27 EST 2024. Contains 370307 sequences. (Running on oeis4.)