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A158221
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a(n) = 169n + 1.
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2
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170, 339, 508, 677, 846, 1015, 1184, 1353, 1522, 1691, 1860, 2029, 2198, 2367, 2536, 2705, 2874, 3043, 3212, 3381, 3550, 3719, 3888, 4057, 4226, 4395, 4564, 4733, 4902, 5071, 5240, 5409, 5578, 5747, 5916, 6085, 6254, 6423, 6592, 6761, 6930, 7099, 7268
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OFFSET
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1,1
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COMMENTS
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The identity (169*n+1)^2 - (169*n^2 + 2*n)*(13)^2 = 1 can be written as a(n)^2 - A158220(n)*(13)^2 = 1. - Vincenzo Librandi, Feb 02 2012
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LINKS
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FORMULA
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MATHEMATICA
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PROG
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(Magma) I:=[170, 339]; [n le 2 select I[n] else 2*Self(n-1)-Self(n-2): n in [1..50]]; // Vincenzo Librandi, Feb 02 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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