login
The OEIS is supported by
the many generous donors to the OEIS Foundation
.
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
STATUS
approved
