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A188983
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Odd numbers y such that x^2 + y^2 = 13^n with x and y coprime.
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3
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1, 3, 5, 9, 119, 597, 2035, 4449, 239, 56403, 341525, 1315911, 3455641, 3627003, 23161315, 186118929, 815616479, 2474152797, 4241902555, 6712571031, 95420159401, 485257533003, 1671083125805, 3718150825791, 584824319281, 44827014819597, 276564805068235, 1076637637754649, 2864483360640839, 3190610873034597, 18094618450123325
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OFFSET
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0,2
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COMMENTS
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This is also the absolute value of the real part of (3+2i)^n, where i = sqrt(-1). The signed version is A121622.
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LINKS
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MATHEMATICA
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Table[s = Select[PowersRepresentations[13^n, 2, 2], CoprimeQ @@ # &, 1][[1]]; Select[s, OddQ][[1]], {n, 0, 30}]
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PROG
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(Magma) [Integers()!Abs(Real((3+2*Sqrt(-1))^n)): n in [0..30]]; // Bruno Berselli, May 26 2011
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CROSSREFS
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KEYWORD
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nonn
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AUTHOR
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STATUS
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approved
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