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A145323 Numbers x such that there exists n in N : (x+1)^3-x^3=31*n^2. 1
22, 546817, 13288758862, 322943417329657, 7848170914656577702, 190726249245040733996497, 4635029301304809002926304542, 112640481889583219144074318995337, 2737388986245622090334485097298387382, 66524027031100626149725437690471091174177 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

LINKS

Table of n, a(n) for n=1..10.

Index entries for linear recurrences with constant coefficients, signature (24303,-24303,1).

FORMULA

a(n+2) = 24302*a(n+1)-a(n)+12150.

a(n) = -(1/2)+(7/6)*sqrt(93)*{[12151+1260*sqrt(93)]^n*sqrt(93)-[12151-1260*sqrt(93)]^n }+(45/4)*{[12151+1260*sqrt(93)]^n+[12151-1260*sqrt(93)]^n} with n>=0. - Paolo P. Lava, Nov 25 2008

G.f.: x*(23*x^2-12151*x-22) / ((x-1)*(x^2-24302*x+1)). - Colin Barker, Oct 18 2014

EXAMPLE

a(1)=22 because the first relation is : 23^3-22^3=31*7^2.

PROG

(PARI) Vec(x*(23*x^2-12151*x-22) / ((x-1)*(x^2-24302*x+1)) + O(x^20)) \\ Colin Barker, Oct 18 2014

CROSSREFS

Sequence in context: A092212 A238635 A013770 * A267492 A013816 A104789

Adjacent sequences:  A145320 A145321 A145322 * A145324 A145325 A145326

KEYWORD

nonn,easy

AUTHOR

Richard Choulet, Oct 07 2008

EXTENSIONS

Editing and more terms from Colin Barker, Oct 18 2014

STATUS

approved

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Last modified May 22 18:53 EDT 2019. Contains 323481 sequences. (Running on oeis4.)