A088073 Beginning with 11 (concatenation of 1 twice), smallest number which is a concatenation of itself as many (say k) times required, chosen from odd numbers not == 5 (mod 10), in natural order, so that every partial concatenation is prime.

11, 3, 777, 999, 11, 131313131313131313131313131313131313131313

Offset: 0

Author

Amarnath Murthy, Sep 22 2003

Keywords

• base
• nonn

Comments

Numbers chosen are from 1,3,7,9,11,13,17,19,21,23,27,29,... which can produce primes.

Next term has > 2000 digits and is too large to include. - David Wasserman, Jul 01 2005

Crossrefs

Cf. A088074.

Extensions

More terms from David Wasserman, Jul 01 2005