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A157263
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a(n) = 1728*n - 1320.
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3
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408, 2136, 3864, 5592, 7320, 9048, 10776, 12504, 14232, 15960, 17688, 19416, 21144, 22872, 24600, 26328, 28056, 29784, 31512, 33240, 34968, 36696, 38424, 40152, 41880, 43608, 45336, 47064, 48792, 50520, 52248, 53976, 55704, 57432, 59160
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OFFSET
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1,1
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COMMENTS
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The identity (10368*n^2-15840*n+6049)^2-(36*n^2-55*n+21)*(1728*n-1320)^2=1 can be written as A157264(n)^2-A157262(n)*a(n)^2=1. - Vincenzo Librandi, Jan 27 2012
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LINKS
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FORMULA
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E.g.f.: (1728*x - 1320)*exp(x) + 1320. - G. C. Greubel, Feb 04 2018
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MATHEMATICA
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PROG
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(Magma) I:=[408, 2136]; [n le 2 select I[n] else 2*Self(n-1)-Self(n-2): n in [1..50]]; // Vincenzo Librandi, Jan 27 2012
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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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STATUS
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approved
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