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

1,1

Comments

No other terms < 10000.

Links

Table of n, a(n) for n=1..17.

Example

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

Prog

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

Crossrefs

Cf. A171411, A171376.

Sequence in context: A153933 A128601 A034500 * A077325 A148213 A148214

Adjacent sequences: A261452 A261453 A261454 * A261456 A261457 A261458

Keyword

nonn,more

Author

Chai Wah Wu, Aug 20 2015

Status

approved