A233464 a(n) is the smallest natural number m such that 10^10^k + m is prime for k = 0, 1, ...., n.

1, 19, 5641, 1289743, 2578966671

Offset: 0

Author

Farideh Firoozbakht, Mar 13 2014

Keywords

• nonn
• hard
• more

Examples

			29 (=10^1+19) and 10000000019 (=10^10+19) are primes so a(1)=19.
		

Crossrefs

Cf. A129613, A129614, A129615.

Programs

PARI

okm(m, n) = {for (k=0, n, if (!isprime(10^10^k + m), return (0)););return (1);}
a(n) = {m = 0; while (!okm(m, n), m++); m;} \\ Michel Marcus, Mar 16 2014

Extensions

a(4) from Giovanni Resta, Mar 14 2014