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Search: id:A133326
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| A133326 |
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Numbers X such that 2*X^2+41 is a square. |
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+0
1
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| 2, 8, 20, 50, 118, 292, 688, 1702, 4010, 9920, 23372, 57818, 136222, 336988, 793960, 1964110, 4627538, 11447672, 26971268, 66721922, 157200070, 388883860, 916229152
(list; graph; listen)
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OFFSET
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1,1
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COMMENT
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a(24) > 2^31. [From Donovan Johnson (donovan.johnson(AT)yahoo.com), Nov 15 2009]
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FORMULA
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The bisections modulo 2 satisfy the same recurrence relation a(n+2)=6*a(n+1)-a(n)
G.f.: 2*x*(x+1)*(x^2+3*x+1)/(x^2+2*x-1)/(x^2-2*x-1). - R. J. Mathar (mathar(AT)strw.leidenuniv.nl), Nov 14 2007
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CROSSREFS
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Sequence in context: A066857 A146168 A058405 this_sequence A024997 A081157 A099177
Adjacent sequences: A133323 A133324 A133325 this_sequence A133327 A133328 A133329
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KEYWORD
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nonn,new
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AUTHOR
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R. Choulet (richardchoulet(AT)yahoo.fr), Oct 18 2007
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EXTENSIONS
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a(14)-a(23) from Donovan Johnson (donovan.johnson(AT)yahoo.com), Nov 15 2009
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