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 A026447 a(n) = least positive integer > a(n-1) and not a(i)*a(j)+2 for 1<=i
 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 (list; graph; refs; listen; history; text; internal format)
 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: A333214 A108473 A298113 * A194378 A283810 A130231 Adjacent sequences:  A026444 A026445 A026446 * A026448 A026449 A026450 KEYWORD nonn AUTHOR STATUS approved

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Last modified November 28 09:13 EST 2020. Contains 338714 sequences. (Running on oeis4.)