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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

G. C. Greubel, Table of n, a(n) for n = 0..335

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

Adjacent sequences:  A123390 A123391 A123392 * A123394 A123395 A123396

KEYWORD

nonn

AUTHOR

Mohamed Bouhamida, Oct 14 2006

EXTENSIONS

More terms from Max Alekseyev, Nov 13 2009

STATUS

approved

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Last modified November 27 03:56 EST 2021. Contains 349345 sequences. (Running on oeis4.)