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Search: id:A157331
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| A157331 |
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a(n)=128*n^2-32*n+1 (n>0) |
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+0
3
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| 97, 449, 1057, 1921, 3041, 4417, 6049, 7937, 10081, 12481, 15137, 18049, 21217, 24641, 28321, 32257, 36449, 40897, 45601, 50561, 55777, 61249, 66977, 72961, 79201, 85697, 92449, 99457, 106721, 114241, 122017, 130049, 138337, 146881
(list; graph; listen)
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OFFSET
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1,1
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COMMENT
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If A=[A033991] n(4n-1) (for n>0, 3,14,33,60,95,...,); Y=[A157330] 64*n-8 (56,120,184,...,); X=[A157331] 128*n^2-32*n+1 (97,449,1057,...,) ; , we have for all terms, Pell's equation X^2-A*Y^2=1. Example: 97^2-3*56^2=1; 449^2-14*120^2=1; 1057^2-33*184^2=1; 1921^2-60*248^2=1.
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LINKS
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Vincenzo Librandi, X^2-AY^2=1
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FORMULA
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a(n)=128*n^2-32*n+1 (n>0)
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EXAMPLE
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For n=1, a(1)=97; n=2, a(2)=449; n=3, a(3)=1057;
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CROSSREFS
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Cf. A033991, A157330
Sequence in context: A050666 A160440 A107213 this_sequence A142834 A125646 A142574
Adjacent sequences: A157328 A157329 A157330 this_sequence A157332 A157333 A157334
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KEYWORD
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nonn
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AUTHOR
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Vincenzo Librandi (vincenzo.librandi(AT)tin.it), Feb 27 2009
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