A261455 Numbers n such that 1+131*10^(n-1)+100^n is prime.

2, 4, 13, 30, 73, 82, 120, 168, 227, 422, 433, 451, 607, 612, 798, 1527, 6958

Offset: 1

Author

Chai Wah Wu, Aug 20 2015

Keywords

• nonn
• more

Comments

No other terms < 10000.

Examples

			For n=2, 11311 is prime.
For n=3, 1013101 is not prime.
For n=4, 100131001 is prime.
		

Crossrefs

Cf. A171411, A171376.

Programs

PARI

isok(n)=isprime(1+131*10^(n-1)+100^n) \\ Anders Hellström, Aug 20 2015