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A145696
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Numbers Y such that 111*Y^2+37 is a square.
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1
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7, 4137, 2440823, 1440081433, 849645604647, 501289466660297, 295759935683970583, 174497860764075983673, 102953442090869146396487, 60742356335752032297943657, 35837887284651608186640361143, 21144292755588113078085515130713
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OFFSET
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1,1
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LINKS
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FORMULA
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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
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EXAMPLE
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a(1)=7 because the first relation is 74^2=111*7^2+37.
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MATHEMATICA
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CoefficientList[Series[7 (x + 1)/(x^2 - 590 x + 1), {x, 0, 20}], x] (* Vincenzo Librandi, Oct 21 2014 *)
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PROG
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(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
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CROSSREFS
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KEYWORD
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easy,nonn
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AUTHOR
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EXTENSIONS
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STATUS
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approved
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