A178406 Numbers n such that 10^n - 41 is prime.

2, 6, 8, 12, 14, 47, 88, 130, 414, 1388, 1932, 4106, 4412, 12870, 22956, 23932, 27312, 35316, 37169, 43873, 150029

Offset: 1

Author

Robert Price, Dec 21 2010

Keywords

• more
• nonn

Comments

The next term, if one exists, is >100000. - Robert Price, Apr 25 2011

a(22) > 2.5*10^5. - Robert Price, Apr 12 2015

Examples

			10^6 - 41 = 999959 which is a prime number.
		

Links

• Makoto Kamada, Near-repdigit numbers of the form AA...AABA.
• Makoto Kamada, Prime numbers of the form 99...9959.
• Index entries for primes involving repunits.

Crossrefs

Cf. A108330, A108328.

Programs

Mathematica

m=1000; For[n=1, n
				

PARI

is(n)=ispseudoprime(10^n-41) \\ Charles R Greathouse IV, Jun 13 2017

Extensions

a(20)=43873 from Robert Price, Apr 25 2011

a(21) from Kamada data by Robert Price, Apr 12 2015