|
Search: id:A161682
|
|
|
| A161682 |
|
Primes that are not of the form x^3-y^2. |
|
+0
1
|
|
| 3, 5, 17, 29, 31, 37, 41, 43, 59, 73, 97, 101, 103, 113, 131, 137, 149, 157, 163, 173, 179, 181, 197, 211, 227, 229, 241
(list; graph; listen)
|
|
|
OFFSET
|
1,1
|
|
|
COMMENT
|
The current values are conjectural as they have been reduced from a finite list
of values x^3-y^2 within a search radius x,y < 10000.
Conjecture: The sequence is infinite.
|
|
FORMULA
|
A000040 \ A161681 .
|
|
PROGRAM
|
(PARI) diffcubesq(n) =
{
local(a, c=0, c2=0, j, k, y);
a=vector(floor(n^2/log(n^2)));
for(j=1, n,
for(k=1, n, y=j^3-k^2; if(ispseudoprime(y), c++; a[c]=y; ); );
);
a=vecsort(a);
for(j=2, c/2,
if(a[j]!=a[j-1], c2++; print1(a[j]", "); if(c2>100, break); );
);
}
|
|
CROSSREFS
|
Sequence in context: A032619 A030077 A058580 this_sequence A079373 A038703 A163586
Adjacent sequences: A161679 A161680 A161681 this_sequence A161683 A161684 A161685
|
|
KEYWORD
|
more,nonn
|
|
AUTHOR
|
Cino Hilliard (hillcino368(AT)hotmail.com), Jun 16 2009
|
|
EXTENSIONS
|
Worthless link removed by R. J. Mathar (mathar(AT)strw.leidenuniv.nl), Jul 16 2009
|
|
|
Search completed in 0.002 seconds
|
