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

 

Logo


Hints
(Greetings from The On-Line Encyclopedia of Integer Sequences!)
A009051 Expansion of e.g.f. cos(sin(x)/cosh(x)), even powers only. 1
1, -1, 17, -457, 19777, -1305489, 122670033, -15462740633, 2502900454401, -504155298072609, 123438576028985873, -36064963500185608553, 12385279694301347665473, -4936243039568368083279793, 2258619438301840395444067537, -1175352020113183347337766918201 (list; graph; refs; listen; history; text; internal format)
OFFSET

0,3

LINKS

G. C. Greubel, Table of n, a(n) for n = 0..238

MATHEMATICA

With[{nn=30}, Take[CoefficientList[Series[Cos[Sin[x]/Cosh[x]], {x, 0, nn}], x] Range[ 0, nn]!, {1, -1, 2}]] (* Harvey P. Dale, Mar 27 2013 *)

PROG

(PARI) x='x+O('x^60); v=Vec(serlaplace(cos(sin(x)/cosh(x)))); vector(#v\2, n, v[2*n-1]) \\ G. C. Greubel, Jul 23 2018

CROSSREFS

Sequence in context: A012117 A271438 A122430 * A035276 A196484 A196717

Adjacent sequences:  A009048 A009049 A009050 * A009052 A009053 A009054

KEYWORD

sign

AUTHOR

R. H. Hardin

EXTENSIONS

Extended with signs by Olivier Gérard, Mar 15 1997

More terms from Harvey P. Dale, Mar 27 2013

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
The OEIS Community | Maintained by The OEIS Foundation Inc.

License Agreements, Terms of Use, Privacy Policy. .

Last modified March 21 12:04 EDT 2019. Contains 321369 sequences. (Running on oeis4.)