OFFSET
1,1
COMMENTS
The function x^n -y^(n-1) has some prime values if x and y are covering the first quadrant. The smallest of these primes defines a(n).
EXAMPLE
3^1 - 1^0 = 2, 2^2 - 2 = 2, 3^3 - 5^2 = 2, so 2,2,2 are the first 3 entries.
PROG
(PARI) diffpowers(n, m) =
{
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^m-k^(m-1);
if(ispseudoprime(y), c++; a[c]=y; );
);
);
a=vecsort(a);
for(j=2, length(a),
if(a[j]!=a[j-1]&&a[j]!=0, c2++; print1(a[j]", "); if(c2>100, break); );
);
}
CROSSREFS
KEYWORD
nonn
AUTHOR
Cino Hilliard, Jun 17 2009
EXTENSIONS
Definition reworded - R. J. Mathar, Aug 30 2010
STATUS
approved