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Search: id:A133275
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| A133275 |
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Numbers X such that 30*X^2-45 is a square. |
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+0
1
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| 3, 63, 1383, 30363, 666603, 14634903, 321301263, 7053992883, 154866542163, 3400009934703, 74645352021303, 1638797734533963, 35978904807725883, 789897108035435463, 17341757471971854303, 380728767275345359203
(list; graph; listen)
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OFFSET
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1,1
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FORMULA
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a(n+2)=22*a(n+1)-a(n) ; a(n+1)=11*a(n)+2*(30*a(n)^2-45)^0.5
G.f.: -3*x*(-1+x)/(1-22*x+x^2). - R. J. Mathar (mathar(AT)strw.leidenuniv.nl), Nov 14 2007
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EXAMPLE
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a(n)=(3/2)*[11+2*sqrt(30)]^n+(1/4)*[11+2*sqrt(30)]^n*sqrt(30)+(3/2)*[11-2*sqrt(30)]^n-(1/4) *sqrt(30)*[11-2*sqrt(30)]^n, with n>=0 [From Paolo P. Lava (ppl(AT)spl.at), Aug 06 2008]
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CROSSREFS
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Adjacent sequences: A133272 A133273 A133274 this_sequence A133276 A133277 A133278
Sequence in context: A046181 A120053 A139293 this_sequence A123687 A053857 A037108
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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), Oct 16 2007
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EXTENSIONS
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More terms from Paolo P. Lava (ppl(AT)spl.at), Aug 06 2008
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