login
This site is supported by donations to The OEIS Foundation.

 

Logo

Annual Appeal: Please make a donation (tax deductible in USA) to keep the OEIS running. Over 5000 articles have referenced us, often saying "we discovered this result with the help of the OEIS".

Hints
(Greetings from The On-Line Encyclopedia of Integer Sequences!)
A009178 Expansion of cosh(x)*cosh(log(1+x)). 0
1, 0, 2, -3, 19, -90, 556, -3885, 31109, -279972, 2799766, -30797415, 369569047, -4804397598, 67261566464, -1008923496945, 16142775951241, -274427191171080, 4939689441079594, -93854099380512267, 1877081987610245531 (list; graph; refs; listen; history; text; internal format)
OFFSET

0,3

LINKS

Table of n, a(n) for n=0..20.

FORMULA

a(n) ~ n! * (-1)^n * (exp(-1) + exp(1))/4. - Vaclav Kotesovec, Jan 22 2015

MATHEMATICA

With[{nn=20}, CoefficientList[Series[Cosh[x]Cosh[Log[1+x]], {x, 0, nn}], x]Range[0, nn]!] (* Harvey P. Dale, Feb 02 2012 *)

CROSSREFS

Sequence in context: A143893 A262957 A072263 * A141508 A119344 A072877

Adjacent sequences:  A009175 A009176 A009177 * A009179 A009180 A009181

KEYWORD

sign,easy

AUTHOR

R. H. Hardin

EXTENSIONS

Extended with signs by Olivier Gérard, Mar 15 1997

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 December 6 03:02 EST 2016. Contains 278771 sequences.