OFFSET
1,1
COMMENTS
Larger values not certified.
Some of the larger entries may only correspond to probable primes.
EXAMPLE
a(2)=5 because (10-5)*(10-4)*(10-3)*(10-2)*(10-1) + 1 = 15121 is prime.
MATHEMATICA
f[n_] := 10^Length[IntegerDigits[n]] - n; p = 1; Do[p *= f[n]; If[PrimeQ[p + 1], Print[n]], {n, 4635}] (* Ryan Propper, May 20 2006 *)
CROSSREFS
KEYWORD
more,nonn,base
AUTHOR
Jason Earls, Aug 01 2005
EXTENSIONS
More terms from Ryan Propper, May 20 2006
STATUS
approved