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A123115 Values of Y satisfying the equation (X-Y)^4-2XY=0 with integer X>=Y>=0. 1
0, 2, 96, 3430, 117504, 3997418, 135828000, 4614348622, 156753156096, 5324999550290, 180893269972704, 6145046403443638, 208750685752224000, 7091378276778928442, 240898110769066766496, 8183444388129896917150 (list; graph; refs; listen; history; text; internal format)
OFFSET

0,2

COMMENTS

Values of X are given by c(n)*(d(n)+1) and listed in A123056.

LINKS

Table of n, a(n) for n=0..15.

Index entries for linear recurrences with constant coefficients, signature (40,-206,40,-1).

FORMULA

a(n) = c(n)*(d(n)-1), where c(0)=0, c(1)=1, c(n)=6*c(n-1)-c(n-2) and d(0)=1, d(1)=3, d(n)=6*d(n-1)-d(n-2).

For n>=4, a(n) = 40*a(n-1) - 206*a(n-2) + 40*a(n-3) - a(n-4). - Max Alekseyev, Nov 13 2009

G.f.: 2*x*(x^2+8*x+1)/((x^2-34*x+1)*(x^2-6*x+1)). - Colin Barker, Nov 04 2012

MATHEMATICA

LinearRecurrence[{40, -206, 40, -1}, {0, 2, 96, 3430}, 20] (* Harvey P. Dale, May 28 2015 *)

CROSSREFS

Cf. A123056.

Sequence in context: A282436 A069121 A157065 * A119696 A264542 A064069

Adjacent sequences:  A123112 A123113 A123114 * A123116 A123117 A123118

KEYWORD

nonn,easy

AUTHOR

Mohamed Bouhamida (bhmd95(AT)yahoo.fr), Sep 28 2006

EXTENSIONS

More terms from Max Alekseyev, Nov 13 2009

STATUS

approved

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Last modified December 14 05:36 EST 2019. Contains 329978 sequences. (Running on oeis4.)