A197944 Least k such that x^6 + k produces composite numbers for x=1..n and prime for x=n+1.

3, 14, 31, 24, 23, 160, 225, 56, 171, 186, 53, 144, 235, 74, 591, 120, 5, 390, 51, 26, 189, 204, 77, 696, 21, 308, 13, 528, 149, 1848, 519, 38, 2053, 48, 131, 544, 1155, 176, 141, 480, 83, 474, 1437, 656, 2041, 168, 203, 258, 2193, 50, 1249, 534, 11, 3276, 111

Offset

1,1

Links

Table of n, a(n) for n=1..55.

Mathematica

Table[k = 0; While[! (Union[PrimeQ[Range[n]^6 + k]] == {False} && PrimeQ[(n + 1)^6 + k]), k++]; k, {n, 55}] (* T. D. Noe, Oct 19 2011 *)

Crossrefs

Cf. A197955.

Sequence in context: A031049 A014696 A235137 * A071396 A032525 A294420

Adjacent sequences: A197941 A197942 A197943 * A197945 A197946 A197947

Keyword

nonn

Author

Arkadiusz Wesolowski, Oct 19 2011

Status

approved