A178433 Numbers n such that 10^n - 63 is prime.

2, 3, 7, 9, 12, 16, 33, 78, 124, 334, 3618, 3682, 3739, 4732, 6676, 16014, 20023, 20364, 66793

Offset: 1

Author

Robert Price, Dec 21 2010

Keywords

• more
• nonn

Comments

The next term, if it exists, is > 100000.

See Kamada link - primecount.txt for terms, primesize.txt for discovery details including probable or proved primes - search on "99937".

Examples

			10^3 - 63 = 937 which is a prime number.
		

Links

• Makoto Kamada, List of near-repdigit-related prime numbers.
• Index entries for primes involving repunits.

Crossrefs

Cf. A108330, A108328.

Programs

Mathematica

nMax=1000; Do[If[PrimeQ[10^n-63], Print[n]], {n, nMax}]

PARI

is(n)=ispseudoprime(10^n-63) \\ Charles R Greathouse IV, Jun 13 2017

Extensions

a(19)=66793 from Robert Price, May 29 2011