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 A116998 a(n) is the smallest number having no fewer distinct prime factors than any predecessor; a(1) = 1. 5
 1, 2, 3, 4, 5, 6, 10, 12, 14, 15, 18, 20, 21, 22, 24, 26, 28, 30, 42, 60, 66, 70, 78, 84, 90, 102, 105, 110, 114, 120, 126, 130, 132, 138, 140, 150, 154, 156, 165, 168, 170, 174, 180, 182, 186, 190, 195, 198, 204, 210, 330, 390, 420, 462, 510, 546, 570, 630, 660 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,2 COMMENTS A001221(a(n)) <= A001221(a(n+1)); A002110 is a subsequence. LINKS Alois P. Heinz, Table of n, a(n) for n = 1..2500 MAPLE a:= proc(n) option remember; local k, t;       t:= nops(ifactors(a(n-1))[2]);       for k from 1+a(n-1) while nops(ifactors(k)[2])= nu, Return[k]]]; Array[a, 80] (* Jean-François Alcover, Apr 11 2017 *) CROSSREFS Cf. A029744. Cf. A001221 (omega), A002110 (primorial numbers). Sequence in context: A210184 A015853 A018642 * A285614 A078931 A018779 Adjacent sequences:  A116995 A116996 A116997 * A116999 A117000 A117001 KEYWORD nonn AUTHOR Reinhard Zumkeller, Apr 03 2006 STATUS approved

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Last modified March 23 10:55 EDT 2019. Contains 321424 sequences. (Running on oeis4.)