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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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2
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2, 757, 228762, 69085517, 20863597522, 6300737366277, 1902801821018282, 574639849210155037, 173539331659645803042, 52408303521363822363797, 15827134124120214708063802
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OFFSET
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1,1
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COMMENTS
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a(1)=2 because 3^3-2^3=19*1
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LINKS
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Table of n, a(n) for n=1..11.
Index to sequences with linear recurrences with constant coefficients, signature (303,-303,1).
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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, Nov 25 2008]
G.f. x*(-2-151*x+3*x^2) / ( (x-1)*(x^2-302*x+1) ). - R. J. Mathar, Nov 27 2011
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CROSSREFS
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Cf. A145123.
Sequence in context: A072384 A109949 A151591 * A102969 A179960 A167448
Adjacent sequences: A145121 A145122 A145123 * 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, Oct 02 2008
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STATUS
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approved
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