A186538 Numbers n>0 such that 666*10^n+7 is prime.

25, 26, 28, 33, 49, 80, 81, 133, 179, 202, 222, 271, 411, 588, 682, 1039, 2403, 5802, 11544, 12484, 41047, 46396

Offset: 1

Author

Arkadiusz Wesolowski, Feb 23 2011

Keywords

• nonn
• base
• more

Comments

Some of the larger entries may only correspond to probable primes.

Links

• Chris Caldwell, The Prime Glossary, Beastly prime
• G. L. Honaker, Jr. and Chris Caldwell, Prime Curios! 66600...00007 (28-digits)
• Henri & Renaud Lifchitz, PRP Records
• R. Ondrejka, The Top Ten: a Catalogue of Primal Configurations

Crossrefs

Cf. A186086.

Programs

Mathematica

Select[Range[10^3], PrimeQ[666*10^# + 7] &] (* Arkadiusz Wesolowski, Sep 08 2011 *)

Extensions

a(21) from Arkadiusz Wesolowski, May 25 2011

a(22) from Arkadiusz Wesolowski, May 28 2011