login
This site is supported by donations 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

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

CROSSREFS

Sequence in context: A052145 A012061 A012168 * A012038 A012108 A251587

Adjacent sequences:  A012130 A012131 A012132 * A012134 A012135 A012136

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 | Recent | More pages
The OEIS Community | Maintained by The OEIS Foundation Inc.

License Agreements, Terms of Use, Privacy Policy. .

Last modified November 20 06:06 EST 2018. Contains 317385 sequences. (Running on oeis4.)