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A156640
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169n^2 + 140n + 29.
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4
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29, 338, 985, 1970, 3293, 4954, 6953, 9290, 11965, 14978, 18329, 22018, 26045, 30410, 35113, 40154, 45533, 51250, 57305, 63698, 70429, 77498, 84905, 92650, 100733, 109154, 117913, 127010, 136445, 146218, 156329, 166778
(list; graph; refs; listen; history; internal format)
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OFFSET
| 0,1
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COMMENTS
| The identity (57122*n^2+47320*n+9801)^2-(169*n^2+140*n+29)*(4394*n+1820)^2=1 can be written as A156735(n)^2-a(n)*A156636(n)^2=1.
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LINKS
| Vincenzo Librandi, Table of n, a(n) for n = 0..10000
Index to sequences with linear recurrences with constant coefficients, signature (3,-3,1).
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FORMULA
| a(n) = 3*a(n-1) -3*a(n-2) +a(n-3).
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MATHEMATICA
| LinearRecurrence[{3, -3, 1}, {29, 338, 985}, 50]
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PROG
| (MAGMA) I:=[29, 338, 985]; [n le 3 select I[n] else 3*Self(n-1)-3*Self(n-2)+1*Self(n-3): n in [1..50]];
(PARI) a(n)=169n^2+140n+29 \\ Charles R Greathouse IV, Dec 23 2011
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CROSSREFS
| Cf. A156636, A156718, A156735.
Sequence in context: A057131 A160442 A125417 * A022689 A077516 A142278
Adjacent sequences: A156637 A156638 A156639 * A156641 A156642 A156643
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KEYWORD
| nonn,easy
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AUTHOR
| Vincenzo Librandi (vincenzo.librandi(AT)tin.it), Feb 15 2009
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EXTENSIONS
| Edited by Charles R Greathouse IV (charles.greathouse(AT)case.edu), Jul 25 2010
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