A026421 a(n) = least positive integer > a(n-1) and not a(i)*a(j) for 1<=i<j<=n.

3, 4, 5, 6, 7, 8, 9, 10, 11, 13, 14, 16, 17, 19, 22, 23, 25, 26, 29, 31, 34, 37, 38, 41, 43, 46, 47, 49, 53, 58, 59, 61, 62, 67, 71, 73, 74, 79, 81, 82, 83, 86, 89, 94, 97, 101, 103, 105, 106, 107, 108, 109, 113, 118, 120, 121, 122, 127, 131

Offset

1,1

Links

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

Formula

a(n) = A026417(n+1). - R. J. Mathar, May 28 2008

Mathematica

a = {3, 4}; used = {a[[1]]*a[[2]]}; Do[k = a[[-1]] + 1; While[MemberQ[used, k], k++]; used = Union[used, k*a]; AppendTo[a, k], {n, 3, 60}]; a (* Ivan Neretin, Mar 07 2016 *)

Crossrefs

Cf. A026416 and references therein.

Sequence in context: A052404 A298112 A026417 * A026481 A338477 A039211

Adjacent sequences: A026418 A026419 A026420 * A026422 A026423 A026424

Keyword

nonn

Author

Clark Kimberling

Status

approved