A026460 a(n) = least positive integer > a(n-1) and not a(i)*a(j)-2 for 1<=i<=j<=n, n >= 2.

1, 3, 4, 5, 6, 8, 9, 11, 12, 15, 17, 19, 20, 21, 24, 26, 27, 29, 32, 33, 35, 36, 37, 39, 40, 41, 44, 45, 47, 48, 50, 51, 54, 56, 57, 59, 60, 63, 65, 67, 68, 69, 71, 72, 75, 77, 80, 81, 84, 87, 89, 90, 91, 92, 95, 96, 99, 101, 104, 105

Offset

1,2

Links

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

Mathematica

a = {1, 3}; 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. A026453 and references therein.

Sequence in context: A298007 A026363 A124678 * A026464 A191885 A292868

Adjacent sequences: A026457 A026458 A026459 * A026461 A026462 A026463

Keyword

nonn

Author

Clark Kimberling

Status

approved