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Search: id:A157728
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| A157728 |
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a(n)=3906250*n-267000 (n>0) |
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+0
3
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| 3639250, 7545500, 11451750, 15358000, 19264250, 23170500, 27076750, 30983000, 34889250, 38795500, 42701750, 46608000, 50514250, 54420500, 58326750, 62233000, 66139250, 70045500, 73951750, 77858000, 81764250, 85670500
(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=[A157727] 15625*n.^2-2136*n+73 (13562, 58301, 134290, ,..,); Y=[A157728] 3906250*n- 267000 (3639250, 7545500,..,); X=[A157729] 488281250*n^2-66750000*n + 2281249 (423812499, 1821906249,..,), we have, for all terms, Pell's equation X^2-A*Y^2=1. Example: 423812499^2-13562*3639250^2=1; 1821906249^2-58301*7545500^2=1.
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LINKS
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Edward Everett Withford, Pell Equation
Wolfram MathWorld, Pell Equation
Vincenzo Librandi, X^2-AY^2=1
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FORMULA
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a(n)=3906250*n-267000 (n>0)
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EXAMPLE
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For n=1, a(1)=3639250; n=2, a(2)=7545500; n=3, a(3)=11451750
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CROSSREFS
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Cf. A157727, A157729
Sequence in context: A133132 A071552 A053501 this_sequence A090074 A114686 A080657
Adjacent sequences: A157725 A157726 A157727 this_sequence A157729 A157730 A157731
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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 05 2009
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