A026445 a(n) = least positive integer > a(n-1) and not a(i)*a(j)+2 for 1<=i<j<=n.

2, 3, 4, 5, 6, 7, 9, 11, 13, 15, 18, 19, 21, 25, 27, 31, 33, 34, 36, 39, 42, 43, 45, 48, 49, 50, 51, 53, 55, 58, 60, 61, 63, 66, 69, 71, 72, 73, 75, 76, 81, 82, 84, 85, 87, 89, 90, 91, 94, 96, 99, 103, 105, 106, 109, 111, 113, 114, 115, 117

Offset

1,1

Links

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

Mathematica

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

Crossrefs

Cf. A026443 and references therein.

Sequence in context: A008725 A275673 A347327 * A279078 A308627 A330500

Adjacent sequences: A026442 A026443 A026444 * A026446 A026447 A026448

Keyword

nonn

Author

Clark Kimberling

Status

approved