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Search: id:A145124
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| A145124 |
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Numbers x such that there exists n in N : (x+1)^3-x^3=19*n^2 |
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+0
2
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| 2, 757, 228762, 69085517, 20863597522, 6300737366277, 1902801821018282, 574639849210155037, 173539331659645803042, 52408303521363822363797, 15827134124120214708063802
(list; graph; listen)
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OFFSET
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1,1
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COMMENT
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a(1)=2 because 3^3-2^3=19*1
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FORMULA
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a(n+2)=302*a(n+1)-a(n)+150
a(n)=-(1/2)+(5/4)*{[151+20*sqrt(57)]^n+[151-20*sqrt(57)]^n}-(1/6)*sqrt(57)*{[151-20 *sqrt(57)]^n-[151+20*sqrt(57)]^n}, with n>=0 [From Paolo P. Lava (ppl(AT)spl.at), Nov 25 2008]
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CROSSREFS
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Sequence in context: A072384 A109949 A151591 this_sequence A102969 A167448 A078169
Adjacent sequences: A145121 A145122 A145123 this_sequence A145125 A145126 A145127
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KEYWORD
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easy,nonn
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AUTHOR
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Richard Choulet (richardchoulet(AT)yahoo.fr), Oct 02 2008
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