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Search: id:A157651
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| A157651 |
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a(n)=100*n^2-49*n+6 (n>0) |
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+0
3
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| 57, 308, 759, 1410, 2261, 3312, 4563, 6014, 7665, 9516, 11567, 13818, 16269, 18920, 21771, 24822, 28073, 31524, 35175, 39026, 43077, 47328, 51779, 56430, 61281, 66332, 71583, 77034, 82685, 88536, 94587, 100838, 107289, 113940, 120791, 127842
(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=[A157651] 100*n.^2-49*n +6 (57, 308, 759, 1410 ,..,); Y=[A157627] 8000*n-1960 (6040, 14040, 22040..,); X=[A157628] 80000*n^2-39200*n+4801 (45601, 246401, 607201,.,), we have, for all terms, Pell's equation X^2-A*Y^2=1. Example: 45601^2-57*6040^2=1; 246401^2-308*14040^2=1; 607201^2-759*22040^2=1.
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LINKS
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Wolfram MathWorld, Pell Equation
Vincenzo Librandi, X^2-AY^2=1
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FORMULA
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a(n)=100*n^2-49*n+6 (n>0)
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EXAMPLE
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For n=1, a(1)=57; n=2, a(2)=308; n=3, a(3)=759
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CROSSREFS
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Cf. A157652, A157653
Sequence in context: A158668 A145296 A048422 this_sequence A043399 A038482 A097200
Adjacent sequences: A157648 A157649 A157650 this_sequence A157652 A157653 A157654
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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), Mar 03 2009
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