login
The OEIS is supported by
the many generous donors to the OEIS Foundation
.
Hints
(Greetings from
The On-Line Encyclopedia of Integer Sequences
!)
A012838
sec(sec(x)*tanh(x))=1+1/2!*x^2+9/4!*x^4+297/6!*x^6+14385/8!*x^8...
0
1, 1, 9, 297, 14385, 1207729, 143876601, 23841581337, 5193194291937, 1442318342390497, 497436148816555113, 208516037618871269001, 104439610892072605613073, 61591265237655555392072593
(
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:
A129934
A003303
A371252
*
A216966
A211077
A211082
Adjacent sequences:
A012835
A012836
A012837
*
A012839
A012840
A012841
KEYWORD
nonn
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 August 20 14:15 EDT 2024. Contains 375336 sequences. (Running on oeis4.)