A026454 - OEIS

A026454

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

1, 3, 4, 5, 6, 7, 8, 9, 11, 12, 14, 15, 17, 20, 21, 23, 24, 27, 29, 32, 35, 36, 37, 39, 41, 44, 45, 47, 48, 50, 51, 55, 56, 57, 59, 60, 62, 63, 65, 69, 71, 72, 74, 76, 77, 80, 81, 84, 87, 89, 91, 92, 93, 95, 99, 101, 102, 104, 105, 107

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OFFSET

1,2

LINKS

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

MATHEMATICA

a = {1, 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. A026453 and references therein.

Sequence in context: A039181 A298111 A299534 * A026458 A059109 A189080

Adjacent sequences: A026451 A026452 A026453 * A026455 A026456 A026457

KEYWORD

nonn

AUTHOR

Clark Kimberling

EXTENSIONS

Definition corrected by Harvey P. Dale, Jun 12 2013

STATUS

approved