A145335 Numbers n such that there exists x in N : (x+1)^3-x^3=43*n^2.

7, 235963, 7954312723, 268139881656367, 9038995402681818847, 304704534756264231676003, 10271589857594671847116242283, 346255293794811853210024295683927, 11672265943551517714115247160388936887, 393472084610866368348013128566686766776843

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) = 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.

Mathematica

LinearRecurrence[{33710, -1}, {7, 235963}, 15] (* Paolo Xausa, Jan 17 2024 *)

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