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A145530 Numbers x such that there exists n in N with (x+1)^3-x^3=91*n^2. 1
5, 8002, 11635629, 16918197290, 24599047224757, 35766997746600114, 52005190124509341725, 75615510674038836268762, 109944900514862343425438949, 159859809733099173301751963810, 232436053407025683118403929941517, 337961861794005610154986012383002634 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

LINKS

Table of n, a(n) for n=1..12.

Index entries for linear recurrences with constant coefficients, signature (1455,-1455,1).

FORMULA

a(n+2) = 1454*a(n+1)-a(n)+726.

a(n) = -(1/2)+(11/4)*{[727-44*sqrt(273)]^n+[727+44*sqrt(273)]^n}-(1/6)*sqrt(273)*{[727-44 *sqrt(273)]^n-[727+44*sqrt(273)]^n} with n>=0. - Paolo P. Lava, Nov 25 2008

G.f.: x*(6*x^2-727*x-5) / ((x-1)*(x^2-1454*x+1)). - Colin Barker, Oct 18 2014

EXAMPLE

a(1)=5 because the first relation is (5+1)^3-5^3=91*1^2.

PROG

(PARI) Vec(x*(6*x^2-727*x-5)/((x-1)*(x^2-1454*x+1)) + O(x^20)) \\ Colin Barker, Oct 18 2014

CROSSREFS

Sequence in context: A203689 A116140 A243235 * A067816 A076629 A052027

Adjacent sequences:  A145527 A145528 A145529 * A145531 A145532 A145533

KEYWORD

easy,nonn

AUTHOR

Richard Choulet, Oct 12 2008, Oct 13 2008

EXTENSIONS

Editing and more terms from Colin Barker, Oct 18 2014

STATUS

approved

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Last modified May 14 13:45 EDT 2021. Contains 343884 sequences. (Running on oeis4.)