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A154359
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a(n) = 1250*n^2 - 700*n + 99.
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5
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99, 649, 3699, 9249, 17299, 27849, 40899, 56449, 74499, 95049, 118099, 143649, 171699, 202249, 235299, 270849, 308899, 349449, 392499, 438049, 486099, 536649, 589699, 645249, 703299, 763849, 826899, 892449, 960499, 1031049
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OFFSET
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0,1
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COMMENTS
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The identity (1250*n^2 - 700*n + 99)^2 - (25*n^2 - 14*n + 2)*(250*n - 70)^2 = 1 can be written as a(n)^2 - A154357(n)*A154361(n)^2 = 1. See also the third comment in A154357.
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LINKS
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FORMULA
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E.g.f.: (99 + 550*x + 1250*x^2)*exp(x). - G. C. Greubel, Sep 15 2016
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MATHEMATICA
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LinearRecurrence[{3, -3, 1}, {99, 649, 3699}, 50] (* Vincenzo Librandi, Feb 21 2012 *)
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PROG
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(PARI) for(n=0, 40, print1(1250*n^2-700*n+99", ")); \\ Vincenzo Librandi, Feb 21 2012
(Magma) [1250*n^2-700*n+99: n in [0..40]]; // Bruno Berselli, Sep 15 2016
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CROSSREFS
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KEYWORD
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nonn,easy
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AUTHOR
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EXTENSIONS
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STATUS
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approved
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