A026447 a(n) = least positive integer > a(n-1) and not a(i)*a(j)+2 for 1<=i<j<=n.

3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 15, 16, 18, 19, 21, 24, 25, 27, 28, 31, 33, 36, 39, 40, 43, 45, 48, 49, 51, 53, 55, 60, 61, 63, 64, 69, 70, 71, 73, 75, 76, 81, 84, 85, 87, 88, 89, 91, 94, 96, 99, 100, 103, 104, 105, 108, 109, 111, 113

Offset

1,1

Links

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

Mathematica

a = {3, 4}; 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: A363768 A108473 A298113 * A194378 A283810 A130231

Adjacent sequences: A026444 A026445 A026446 * A026448 A026449 A026450

Keyword

nonn

Author

Clark Kimberling

Status

approved