A153434 a(n) is the smallest number m such that all n numbers m+1, m.m+1, ..., m.m. ... .m+1 are prime, where dot means concatenation.

1, 2, 2, 42, 42, 1179990, 243464796

Offset: 1

Author

Farideh Firoozbakht, Apr 01 2009

Keywords

• base
• more
• nonn

Examples

			All 5 numbers 1+42,1+4242,1+424242,1+42424242 & 1+4242424242 are prime and 42
is the smallest such number so a(5)=42.
		

Crossrefs

Cf. A153435.