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A145210
Numbers n such that there exists x in N : (x+1)^3-x^3=67*n^2.
2
31, 31935859, 32900002583179, 33893253661133238151, 34916490989129950608195511, 35970619852057890563395800238939, 37056572865356601788515589497544372899, 38175310800125746976658817253911841716581871, 39327823433144486705018790345018924628507933312591
OFFSET
1,1
FORMULA
a(n+2) = 1030190*a(n+1)-a(n).
a(n) = A145207(n)/4489. - Colin Barker, Oct 19 2014
G.f.: -31*x*(x-1) / (x^2-1030190*x+1). - Colin Barker, Oct 19 2014
a(n) = A145205(n)/134. - Hugo Pfoertner, Apr 08 2024
EXAMPLE
a(1)=31 because the first relation is : 147^3-146^3=67*31^2.
MATHEMATICA
CoefficientList[Series[31 (1 - x)/(x^2 - 1030190 x + 1), {x, 0, 20}], x] (* Vincenzo Librandi, Oct 19 2014 *)
LinearRecurrence[{1030190, -1}, {31, 31935859}, 10] (* Harvey P. Dale, Aug 11 2021 *)
PROG
(PARI) Vec(-31*x*(x-1)/(x^2-1030190*x+1) + O(x^20)) \\ Colin Barker, Oct 19 2014
(Magma) I:=[31, 31935859]; [n le 2 select I[n] else 1030190*Self(n-1)-Self(n-2): n in [1..10]]; // Vincenzo Librandi, Oct 19 2014
CROSSREFS
Sequence in context: A342118 A216791 A324268 * A091308 A023927 A345676
KEYWORD
easy,nonn
AUTHOR
Richard Choulet, Oct 04 2008
EXTENSIONS
Editing and more terms from Colin Barker, Oct 19 2014
STATUS
approved