A211237 Prime numbers p such that x^2 + x + p produces primes for x = 0..8 but not x = 9.

51867197, 85776137, 93685301, 97122197, 107599757, 113575727, 118136267, 232728647, 316973621, 483040757, 564537761, 749930717, 840472307, 901288517, 1559839991, 1696818647, 2251028567, 2469604721, 2796607337, 3098938847, 3152692841, 3344410367

Offset: 1

Author

T. D. Noe, Apr 08 2012

Keywords

• nonn

Comments

The first term is A164926(9).

Links

• T. D. Noe, Table of n, a(n) for n = 1..500

Crossrefs

Cf. A067774, A164926.

Programs

Mathematica

lookfor = 9; t = {}; n = 0; While[Length[t] < 25, n++; c = Prime[n]; i = 1; While[PrimeQ[i^2 + i + c], i++]; If[i == lookfor, AppendTo[t, c]]]; t
Select[Prime[Range[31*10^5,65*10^5]],AllTrue[#+{2,6,12,20,30,42,56,72},PrimeQ] && CompositeQ[#+90]&] (* The program generates the first 6 terms of the sequence. To generate more, increase the second Range constant. *) (* Harvey P. Dale, Nov 02 2021 *)