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Search: id:A144796
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| A144796 |
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Numbers n such that 0.5*(n^2-17) is a square |
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+0
3
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| 5, 215, 4517, 248087, 5212613, 286292183, 6015350885, 330380931095, 6941709708677, 381259308191447, 8010726988462373, 439972911271998743, 9244372002975869765, 507728358348578357975, 10667997280707165246437
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OFFSET
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1,1
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FORMULA
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a(n+2)=1154*a(n+1)-a(n) for the subsequence of the odd and the even indices respectively
a(n)=1154*a(n-2)-a(n-4). G.f.: x(5+215x-1253x^2-23x^3)/((1+34x+x^2)(1-34x+x^2)). [From R. J. Mathar (mathar(AT)strw.leidenuniv.nl), Oct 04 2008]
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EXAMPLE
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a(1)=5 because 0.5*(25-17)=4
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CROSSREFS
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A133301
Sequence in context: A055316 A165208 A004784 this_sequence A119657 A159808 A159317
Adjacent sequences: A144793 A144794 A144795 this_sequence A144797 A144798 A144799
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KEYWORD
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nonn
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AUTHOR
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Richard Choulet (richardchoulet(AT)yahoo.fr), Sep 21 2008
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EXTENSIONS
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More terms from R. J. Mathar (mathar(AT)strw.leidenuniv.nl), Oct 04 2008
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