A191456 Primes p such that the polynomial x^2+x+p generates only primes for x=1..9.

11, 17, 41, 844427, 51448361, 86966771, 122983031, 180078317, 960959381, 1278189947, 1761702947, 1829187287, 2426256797, 2911675511, 3013107257, 4778888351, 5221343711

Offset: 1

Author

Zak Seidov, Jun 02 2011

Keywords

• nonn

Links

• Charles R Greathouse IV, Table of n, a(n) for n = 1..2713

Crossrefs

Generates primes for x=1..k: A001359 (1), A022004 (2), A172454 (3), A187057 (4), A187058 (5), A144051 (6), A187060 (7), A190800 (8), this sequence (9), A191457 (10), A191458 (11), A253592 (12), A253605 (13). Each is by definition a subsequence of preceding sequences.

Subsequence such that x=10 gives a composite number: A211238.

Cf. A160548, A164926.

Programs

PARI

is(n)=for(x=0,9, if(!isprime(x^2+x+n), return(0))); 1 \\ Charles R Greathouse IV, Sep 14 2015