

A088017


Numbers not expressible as sum or difference of a nonzero cube and a nonzero square.


5



6, 14, 16, 21, 27, 29, 32, 34, 42, 46, 51, 58, 59, 62, 66, 69, 70, 75, 77, 78, 84, 85, 86, 88, 90, 93, 96, 102, 103, 110, 111, 114, 115, 123, 125, 130, 133, 137, 140, 144, 149, 157, 158, 160, 162, 165, 166, 173, 176, 178, 179, 181, 182, 183, 187, 194, 201, 202, 203
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OFFSET

1,1


COMMENTS

Numbers n such that neither variant of Mordell's equation y^2=x^3+n (A054504) or y^2=x^3n (A081121) has an integral solution with nonzero x and y.  Jack Brennen, Aug 28 2003


LINKS

Table of n, a(n) for n=1..59.
J. Gebel, Integer points on Mordell curves [Cached copy, after the original web site tnt.math.se.tmu.ac.jp was shut down in 2017]
Eric Weisstein's World of Mathematics, Mordell Curve. Section in World of Mathematics.


EXAMPLE

16 is in the sequence because the only integral solution to Mordell's equation y^2 = x^3 + 16 is (y=4,x=0). 49 is not in the sequence because it can also be expressed as 65^3524^2.


CROSSREFS

Cf. A054504, A081121, A087285, A087286.
Sequence in context: A140330 A242832 A114634 * A206524 A141082 A108977
Adjacent sequences: A088014 A088015 A088016 * A088018 A088019 A088020


KEYWORD

nonn


AUTHOR

Hugo Pfoertner, Sep 18 2003


STATUS

approved



