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A157857
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a(n) = 3600*n^2 - n.
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3
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3599, 14398, 32397, 57596, 89995, 129594, 176393, 230392, 291591, 359990, 435589, 518388, 608387, 705586, 809985, 921584, 1040383, 1166382, 1299581, 1439980, 1587579, 1742378, 1904377, 2073576, 2249975, 2433574, 2624373, 2822372
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OFFSET
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1,1
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COMMENTS
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The identity (103680000*n^2 - 28800*n + 1)^2 - (3600*n^2 - n)*(1728000*n - 240)^2 = 1 can be written as A157859(n)^2 - a(n)*A157858(n)^2 = 1 (see second comment at A157858). - Vincenzo Librandi, Jan 25 2012
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LINKS
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FORMULA
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G.f.: x*(3599 + 3601*x)/(1-x)^3. - Colin Barker, Jan 17 2012
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MATHEMATICA
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LinearRecurrence[{3, -3, 1}, {3599, 14398, 32397}, 40] (* Vincenzo Librandi, Jan 25 2012 *)
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PROG
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(Magma) I:=[3599, 14398, 32397]; [n le 3 select I[n] else 3*Self(n-1)-3*Self(n-2)+1*Self(n-3): n in [1..40]]; // Vincenzo Librandi, Jan 25 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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