A129615 a(n) is the smallest natural number m such that 4^4^k + m is prime for k=0,1,...,n.

1, 1, 15, 385, 137593, 106908087

Offset: 0

Author

Farideh Firoozbakht, May 13 2007

Keywords

• hard
• more
• nonn

Comments

Next term is greater than 3*10^8.

Examples

			For k=0,1,...,5 4^4^k + 106908087 are prime and 106908087 is the smallest number with this property so a(5)=106908087.
		

Crossrefs

Cf. A129613, A129614.