A191456 - OEIS

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

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OFFSET

1,1

LINKS

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

PROG

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

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.

Sequence in context: A331940 A187060 A190800 * A146036 A248482 A267772

Adjacent sequences: A191453 A191454 A191455 * A191457 A191458 A191459

KEYWORD

nonn

AUTHOR

Zak Seidov, Jun 02 2011

STATUS

approved