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Search: id:A157508
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| 1440, 2898, 4356, 5814, 7272, 8730, 10188, 11646, 13104, 14562, 16020, 17478, 18936, 20394, 21852, 23310, 24768, 26226, 27684, 29142, 30600, 32058, 33516, 34974, 36432, 37890, 39348, 40806, 42264, 43722, 45180, 46638, 48096, 49554
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OFFSET
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1,1
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COMMENT
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If A=[A157507] 81*n.^2-2*n (79,320,723,1288,.,); Y=[A157508] 1458*n-18 (1440,2898,4356..,); X=[A157509] 13122*n^2-324*n+1 (12799,51841,117127,.,) ; , we have for all terms, Pell's equation X^2-A*Y^2=1. Example: 12799^2-79*1440^2=1; 51841^2-320*2898^2=1; 117127^2-723*4356^2=1.
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LINKS
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Vincenzo Librandi, X^2-AY^2=1
Wolfram MathWorld, Pell Equation
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FORMULA
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a(n)=1458*n-18 (n>0)
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EXAMPLE
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For n=1, a(1)=1440; n=2, a(2)=2898; n=3, a(3)=4356
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CROSSREFS
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Cf. A157507, A157509
Sequence in context: A101998 A063846 A078095 this_sequence A061221 A023102 A119422
Adjacent sequences: A157505 A157506 A157507 this_sequence A157509 A157510 A157511
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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 02 2009
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