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A145335 Numbers n such that there exists x in N : (x+1)^3-x^3=43*n^2. 1
7, 235963, 7954312723, 268139881656367, 9038995402681818847, 304704534756264231676003, 10271589857594671847116242283, 346255293794811853210024295683927, 11672265943551517714115247160388936887, 393472084610866368348013128566686766776843 (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 (33710,-1).

FORMULA

a(n+2) = 33710*a(n+1)-a(n).

a(n) = (7/2)*{[16855+1484*sqrt(129)]^n+[16855-1484*sqrt(129)]^n}-(53/172)*sqrt(129)*{[16855-1484*sqrt(129)]^n- [16855+1484*sqrt(129)]^n} with n>=0. - Paolo P. Lava, Nov 25 2008

a(n) = A145333(n)/1849. - Colin Barker, Oct 20 2014

G.f.: -7*x*(x-1) / (x^2-33710*x+1). - Colin Barker, Oct 20 2014

EXAMPLE

a(1)=7 because the first relation is : 27^3-26^3=43*7^2.

PROG

(PARI) Vec(-7*x*(x-1)/(x^2-33710*x+1) + O(x^20)) \\ Colin Barker, Oct 20 2014

CROSSREFS

Cf. A145333.

Sequence in context: A297059 A306256 A145322 * A003835 A138878 A050938

Adjacent sequences:  A145332 A145333 A145334 * A145336 A145337 A145338

KEYWORD

easy,nonn

AUTHOR

Richard Choulet, Oct 08 2008

EXTENSIONS

Editing and more terms from Colin Barker, Oct 20 2014

STATUS

approved

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Last modified December 9 02:53 EST 2021. Contains 349625 sequences. (Running on oeis4.)