OFFSET
1,1
EXAMPLE
3,311,311111,31111111111111 are all prime.
31111111111111 = one copy of 3, two copies of 1, three copies of 1, four copies of 11.
PROG
(PARI) { x=3; for(n=2, 50, k=0; until(ispseudoprime(y), k++; y=eval(concat(Str(x), concat(vector(n, i, Str(k))))); ); print1(k, ", "); x=y; ) } \\ Max Alekseyev, May 18 2009
CROSSREFS
KEYWORD
base,hard,nonn
AUTHOR
Amarnath Murthy, Aug 05 2005
EXTENSIONS
More terms from Max Alekseyev, May 18 2009
STATUS
approved