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A145696
Numbers Y such that 111*Y^2+37 is a square.
1
7, 4137, 2440823, 1440081433, 849645604647, 501289466660297, 295759935683970583, 174497860764075983673, 102953442090869146396487, 60742356335752032297943657, 35837887284651608186640361143, 21144292755588113078085515130713
OFFSET
1,1
FORMULA
a(n+2) = 590*a(n+1)-a(n).
G.f.: 7*x*(x+1) / (x^2-590*x+1). - Colin Barker, Oct 21 2014
EXAMPLE
a(1)=7 because the first relation is 74^2=111*7^2+37.
MATHEMATICA
CoefficientList[Series[7 (x + 1)/(x^2 - 590 x + 1), {x, 0, 20}], x] (* Vincenzo Librandi, Oct 21 2014 *)
PROG
(PARI) Vec(7*x*(x+1)/(x^2-590*x+1) + O(x^20)) \\ Colin Barker, Oct 21 2014
(Magma) I:=[7, 4137]; [n le 2 select I[n] else 590*Self(n-1)-Self(n-2): n in [1..15]]; // Vincenzo Librandi, Oct 21 2014
CROSSREFS
Sequence in context: A024100 A069644 A203679 * A361452 A338250 A103856
KEYWORD
easy,nonn
AUTHOR
Richard Choulet, Oct 16 2008
EXTENSIONS
Editing and more terms from Colin Barker, Oct 21 2014
STATUS
approved