

A054504


Numbers n such that Mordell's equation y^2 = x^3 + n has no integral solutions.


33



6, 7, 11, 13, 14, 20, 21, 23, 29, 32, 34, 39, 42, 45, 46, 47, 51, 53, 58, 59, 60, 61, 62, 66, 67, 69, 70, 74, 75, 77, 78, 83, 84, 85, 86, 87, 88, 90, 93, 95, 96, 102, 103, 104, 109, 110, 111, 114, 115, 116, 118, 123, 124, 130, 133, 135, 137, 139, 140, 146, 147, 149, 153, 155
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OFFSET

1,1


COMMENTS

Mordell's equation has a finite number of integral solutions for all nonzero n. Gebel computes the solutions for n < 10^5. Sequence A081121 gives n for which there are no integral solutions to y^2 = x^3  n. See A081119 for the number of integral solutions to y^2 = x^3 + n.  T. D. Noe, Mar 06 2003


REFERENCES

T. M. Apostol, Introduction to Analytic Number Theory, SpringerVerlag, page 192.
J. Gebel, A. Petho and H. G. Zimmer, On Mordell's equation, Compositio Mathematica 110 (3) (1998), 335367.


LINKS

T. D. Noe, Table of n, a(n) for n=1..6603 (from Gebel)
J. Gebel, Integer points on Mordell curves
Eric Weisstein's World of Mathematics, Mordell Curve


MATHEMATICA

m = 155; f[_List] := ( xm = 2 xm; ym = Ceiling[xm^(3/2)];
Complement[Range[m], Outer[Plus, Range[0, ym]^2, Range[xm, xm]^3] //Flatten //Union]); xm=10; FixedPoint[f, {}] (* JeanFrançois Alcover, Apr 28 2011 *)


CROSSREFS

Cf. A081119, A081121.
Sequence in context: A164018 A156793 A081715 * A190612 A224856 A182156
Adjacent sequences: A054501 A054502 A054503 * A054505 A054506 A054507


KEYWORD

nonn,nice


AUTHOR

N. J. A. Sloane, Apr 08 2000


EXTENSIONS

Apostol gives all values of n < 100. Extended by David W. Wilson, Sep 25 2000


STATUS

approved



