A092995 Smallest prime of the form concatenation of prime(n) with itself followed by a 9, or 0 if no such prime exists.

29, 0, 59, 79, 11119, 139, 179, 199, 239, 29292929292929299, 31319, 379, 419, 439, 479, 0, 599, 619, 67679, 719, 739, 797979799, 839, 89899, 979797979, 1019, 1039, 1071071071079, 1091091091099, 1131139, 1279, 1319, 1371371371379, 1399, 1499

Offset: 1

Author

Amarnath Murthy, Mar 28 2004

Keywords

• base
• nonn

Comments

a(16)=0 since the concatenation of 53 with itself, followed by a 9, is always composite. a(36), if it exists, has more than 12000 digits. - Giovanni Resta, Apr 07 2006

Crossrefs

Cf. A092992, A092993, A092994.

Extensions

More terms from Sam Alexander, Jan 09 2005

More terms from Giovanni Resta, Apr 07 2006