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

 

Logo
Hints
(Greetings from The On-Line Encyclopedia of Integer Sequences!)
A123393 Values X satisfying the equation 7(X-Y)^4-2XY=0, where X>=Y. 2
0, 32, 27000, 24193888, 21724523760, 19508551374752, 17518656008529000, 15731733545110199008, 14127079203594427607520, 12686101393056537201642272, 11392104923884436660778375000 (list; graph; refs; listen; history; text; internal format)
OFFSET
0,2
COMMENTS
To find Y values: b(n) = c(n)*(-1+d(n)) which gives: 0, 28, 26880, 24190292, 21724416000, ...
LINKS
FORMULA
a(n) = c(n)*(1+d(n)) with c(0) = 0, c(1) = 2 and c(n) = 30*c(n-1) - c(n-2), d(0) = 1, d(1) = 15 and d(n) = 30*d(n-1) - d(n-2).
From Max Alekseyev, Nov 13 2009: (Start)
For n>=4, a(n) = 928*a(n-1) - 26942*a(n-2) + 928*a(n-3) - a(n-4).
O.g.f.: 8*x*(4*x^2 -337*x +4)/((x^2 -30*x +1)*(x^2 -898*x +1)). (End)
MATHEMATICA
CoefficientList[Series[8*x*(4*x^2 - 337*x + 4)/(x^2 - 30*x + 1)/(x^2 - 898*x + 1), {x, 0, 50}], x] (* G. C. Greubel, Oct 13 2017 *)
PROG
(PARI) x='x+O('x^50); concat([0], Vec(8*x*(4*x^2 -337*x +4)/((x^2 -30*x +1)*(x^2 -898*x +1)))) \\ G. C. Greubel, Oct 13 2017
CROSSREFS
Sequence in context: A227659 A230914 A232596 * A245291 A016937 A074800
KEYWORD
nonn
AUTHOR
Mohamed Bouhamida, Oct 14 2006
EXTENSIONS
More terms from Max Alekseyev, Nov 13 2009
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 March 29 10:59 EDT 2024. Contains 371277 sequences. (Running on oeis4.)