A164926
Least prime p such that x^2+x+p produces primes for x=0..n-1 and composite for x=n.
Original entry on oeis.org
2, 3, 107, 5, 347, 1607, 1277, 21557, 51867197, 11, 180078317, 1761702947, 8776320587, 27649987598537, 291598227841757, 17
Offset: 1
- R. A. Goudsmit, Unusual Prime Number Sequences, Nature, Vol. 214 (June 10, 1967), page 1164.
- R. A. Mollin, Prime-Producing Quadratics, The American Mathematical Monthly, Vol. 104, No. 6 (Jun. - Jul., 1997), pp. 529-544.
Cf.
A005846,
A014556,
A067774,
A210360,
A210361,
A210362,
A210363,
A210364,
A210365,
A211236,
A211237,
A211238,
A211239,
A211240,
A354585.
-
PrimeRun[p_Integer] := Module[{k=0}, While[PrimeQ[k^2+k+p], k++ ]; k]; nn=8; t=Table[0,{nn}]; cnt=0; p=1; While[cnt
A191456
Primes p such that the polynomial x^2+x+p generates only primes for x=1..9.
Original entry on oeis.org
11, 17, 41, 844427, 51448361, 86966771, 122983031, 180078317, 960959381, 1278189947, 1761702947, 1829187287, 2426256797, 2911675511, 3013107257, 4778888351, 5221343711
Offset: 1
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.
Showing 1-2 of 2 results.
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