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!)
A012018 sech(sin(tan(x)))=1-1/2!*x^2+1/4!*x^4+47/6!*x^6+897/8!*x^8... 0
1, -1, 1, 47, 897, 26911, 2176769, 269558351, 38463601409, 6445724731199, 1297792574780417, 307585734223517551, 82426762826906376833, 23816926512873022989919, 6844111898535212011277057 (list; graph; refs; listen; history; text; internal format)
OFFSET
0,4
LINKS
Table of n, a(n) for n=0..14.
CROSSREFS
Sequence in context: A262120 A032626 A009054 * A010963 A234354 A161692
Adjacent sequences: A012015 A012016 A012017 * A012019 A012020 A012021
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 May 21 19:35 EDT 2024. Contains 372738 sequences. (Running on oeis4.)