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A117081
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36*n^2-810*n+2753.
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2
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2753, 1979, 1277, 647, 89, -397, -811, -1153, -1423, -1621, -1747, -1801, -1783, -1693, -1531, -1297, -991, -613, -163, 359, 953, 1619, 2357, 3167, 4049, 5003, 6029, 7127, 8297, 9539, 10853, 12239, 13697, 15227, 16829, 18503, 20249, 22067, 23957, 25919, 27953, 30059, 32237, 34487, 36809, 39203, 41669
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OFFSET
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0,1
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COMMENTS
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The absolute values of a(n) for 0 <= n <= 44 are primes, a(45) = 39203 = 197*199. The positive prime terms are in A050268.
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LINKS
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Vincenzo Librandi, Table of n, a(n) for n = 0..1000
C. Rivera, Problem 12: Prime producing polynomials
Eric Weisstein's World of Mathematics, Prime-Generating Polynomial
Index to sequences with linear recurrences with constant coefficients, signature (3,-3,1).
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FORMULA
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G.f.: (2753-6280*x+3599*x^2)/(1-x)^3. [Colin Barker, May 10 2012]
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MATHEMATICA
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f[n_] := If[Mod[n, 2] == 1, 36*n^2 - 810*n + 2753, 36*n^2 - 810*n + 2753] a = Table[f[n], {n, 0, 100}]
CoefficientList[Series[(2753-6280*x+3599*x^2)/(1-x)^3, {x, 0, 50}], x] (* Vincenzo Librandi, May 12 2012 *)
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PROG
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(PARI) {for(n=0, 46, print1(36*n^2-810*n+2753, ", "))}
(MAGMA) I:=[2753, 1979, 1277]; [n le 3 select I[n] else 3*Self(n-1)-3 *Self(n-2)+Self(n-3): n in [1..50]]; // Vincenzo Librandi, May 12 2012
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CROSSREFS
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Cf. A050268.
Sequence in context: A045151 A122107 A050268 * A164065 A014487 A043665
Adjacent sequences: A117078 A117079 A117080 * A117082 A117083 A117084
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KEYWORD
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sign,easy
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AUTHOR
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Roger L. Bagula, Apr 17 2006
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EXTENSIONS
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Edited by N. J. A. Sloane, Apr 27 2007
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STATUS
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approved
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