A190800 Primes p such that the polynomial x^2 + x + p generates only primes for x = 1..8.

11, 17, 41, 844427, 51448361, 51867197, 85776137, 86966771, 93685301, 97122197, 107599757, 113575727, 118136267, 122983031, 180078317, 232728647, 316973621, 483040757, 564537761, 749930717, 840472307, 901288517, 960959381, 1278189947, 1559839991, 1696818647, 1761702947, 1829187287, 2251028567

Offset: 1

Author

Zak Seidov, Jun 02 2011

Keywords

• nonn

Comments

Subsequence of A187060: a(1..10)=A187060(1,2,3,7,18,19,26,28,31,32).

Links

• Charles R Greathouse IV, Table of n, a(n) for n = 1..10000

Crossrefs

Cf. A187060.

Programs

Mathematica

Select[Prime[Range[110*10^6]],AllTrue[Table[x^2+x+#,{x,8}],PrimeQ]&] (* The program uses the AllTrue function from Mathematica version 10 *) (* Harvey P. Dale, Jul 03 2020 *)

PARI

is(n)=for(x=0,8, if(!isprime(x^2+x+n), return(0))); 1 \\ Charles R Greathouse IV, Sep 14 2015