A026448 a(n) = least positive integer > a(n-1) and not a(i)*a(j)+2 for i<=1<=j<=n.

1, 2, 5, 8, 9, 13, 14, 17, 21, 22, 25, 26, 29, 32, 33, 37, 38, 41, 45, 48, 49, 53, 56, 57, 61, 62, 65, 69, 70, 73, 77, 80, 81, 85, 86, 89, 90, 93, 94, 97, 101, 102, 105, 109, 110, 113, 117, 118, 121, 122, 125, 129, 130, 133, 134, 137, 141

Offset

1,2

Links

Ivan Neretin, Table of n, a(n) for n = 1..1000

Mathematica

a = {1, 2}; used = {a[[1]]^2 + 2, a[[1]]*a[[2]] + 2, a[[2]]^2 + 2}; Do[k = a[[-1]] + 1; While[MemberQ[used, k], k++]; AppendTo[a, k]; used = Union[used, k*a + 2], {n, 3, 60}]; a (* Ivan Neretin, Mar 06 2016 *)

Crossrefs

Cf. A026443 and references therein.

Sequence in context: A190768 A184866 A032684 * A258353 A173286 A243182

Adjacent sequences: A026445 A026446 A026447 * A026449 A026450 A026451

Keyword

nonn

Author

Clark Kimberling

Status

approved