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A157337
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a(n) = 128*n^2 + 32*n + 1.
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2
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161, 577, 1249, 2177, 3361, 4801, 6497, 8449, 10657, 13121, 15841, 18817, 22049, 25537, 29281, 33281, 37537, 42049, 46817, 51841, 57121, 62657, 68449, 74497, 80801, 87361, 94177, 101249, 108577, 116161, 124001, 132097, 140449, 149057
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OFFSET
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1,1
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COMMENTS
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The identity (128*n^2+32*n+1)^2 - (4*n^2+n)*(64*n+8)^2 = 1 can be written as a(n)^2 - A007742(n)*A157336(n)^2 = 1 (see also second part of the comment in A157336). - Vincenzo Librandi, Jan 29 2012
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LINKS
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FORMULA
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E.g.f.: (1 + 160*x + 128*x^2)*exp(x) - 1. - G. C. Greubel, Feb 01 2018
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MATHEMATICA
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LinearRecurrence[{3, -3, 1}, {161, 577, 1249}, 50] (* Vincenzo Librandi, Jan 29 2012 *)
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PROG
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(Magma) I:=[161, 577, 1249]; [n le 3 select I[n] else 3*Self(n-1)-3*Self(n-2)+1*Self(n-3): n in [1..50]]; // Vincenzo Librandi, Jan 29 2012
(PARI) for(n=1, 40, print1(128*n^2 + 32*n + 1", ")); \\ Vincenzo Librandi, Jan 29 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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