OFFSET
1,1
COMMENTS
a(9) > 260843.
MATHEMATICA
Select[Range[50000], PrimeQ[10^(# - 1) - PrimePi[#]] &]
PROG
(PARI) is(n) = ispseudoprime(10^(n-1) - primepi(n)) \\ Michel Marcus, Sep 10 2015
CROSSREFS
KEYWORD
more,nonn
AUTHOR
Robert Price, Sep 09 2015
STATUS
approved