|
|
A080762
|
|
Positive numbers not of the form y^2 - x^3, x and y >= 1.
|
|
2
|
|
|
2, 4, 5, 6, 7, 10, 11, 13, 14, 16, 20, 21, 23, 25, 26, 27, 29, 31, 32, 33, 34, 39, 42, 43, 45, 46, 47, 49, 50, 51, 52, 53, 58, 59, 60, 61, 62, 66, 67, 69, 70, 72, 74, 75, 76, 77, 78, 81, 82, 83, 84, 85, 86, 87, 88, 90, 91, 93, 95, 96, 102, 103, 104, 109, 110, 111, 114, 115
(list;
graph;
refs;
listen;
history;
text;
internal format)
|
|
|
OFFSET
|
1,1
|
|
COMMENTS
|
This is Mordell's equation with the condition that x and y are positive. Sequence A054504 lists the n for which there is no solution to Mordell's equation (positive or negative x and y). Hence, all of those numbers will be in this sequence. Additional terms of this sequence can be determined by looking at the link to Gebel's data. - T. D. Noe, Mar 23 2011
|
|
LINKS
|
|
|
PROG
|
(PARI) diop(n, m) = {f=0; for(p=1, m, f=0; for(x=1, n, y=x*x*x+p; if(issquare(y), f=1); ); if(f==0, print1(p" ")) ) }
|
|
CROSSREFS
|
|
|
KEYWORD
|
nonn
|
|
AUTHOR
|
|
|
STATUS
|
approved
|
|
|
|