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

 

Logo


Hints
(Greetings from The On-Line Encyclopedia of Integer Sequences!)
A126089 E.g.f.: (1-2*x)*sqrt(1-4*x). 1
1, -4, 4, 0, -48, -960, -20160, -483840, -13305600, -415134720, -14529715200, -564583219200, -24135932620800, -1126343522304000, -56992982228582400, -3108708121559040000, -181859425111203840000, -11359219476176732160000, -754576722346025779200000 (list; graph; refs; listen; history; text; internal format)
OFFSET

0,2

LINKS

Table of n, a(n) for n=0..18.

FORMULA

a(n) ~ -2^(2*n-3/2)*n^(n-1)/exp(n). - Vaclav Kotesovec, Jun 02 2013

MATHEMATICA

CoefficientList[Series[(1-2*x)*Sqrt[1-4*x], {x, 0, 20}], x]* Range[0, 20]! (* Vaclav Kotesovec, Jun 02 2013 *)

CROSSREFS

Cf. A126967, A126079.

Sequence in context: A137862 A006805 A030045 * A111848 A204384 A102412

Adjacent sequences:  A126086 A126087 A126088 * A126090 A126091 A126092

KEYWORD

sign

AUTHOR

N. J. A. Sloane, Mar 22 2007

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 February 19 20:17 EST 2019. Contains 320328 sequences. (Running on oeis4.)