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 A137698 a(1)=2. a(n) = the smallest integer > a(n-1) that is not in sequence A137699. A137699(n) = the smallest integer > A137698(n) and not coprime to A137698(n). (A137699(n) = A137698(n) + smallest prime dividing A137698(n).). 2
 2, 3, 5, 7, 8, 9, 11, 13, 15, 16, 17, 19, 20, 21, 23, 25, 27, 28, 29, 31, 32, 33, 35, 37, 39, 41, 43, 44, 45, 47, 49, 50, 51, 53, 55, 57, 59, 61, 63, 64, 65, 67, 68, 69, 71, 73, 75, 76, 77, 79, 80, 81, 83, 85, 87, 88, 89, 91, 92, 93, 95, 97 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,1 LINKS EXAMPLE Checking for the value of a(17): a(16) = 25. Checking 26, we see that A137699(8) = 26 (because a(8) = 13 and 26 is the smallest integer > 13 that is not coprime to 13). So a(17) does not equal 26. 27, however, does not occur in sequence A137699. So a(17) = 27. CROSSREFS Cf. A137699. Sequence in context: A062062 A256133 A078643 * A063743 A144100 A086539 Adjacent sequences:  A137695 A137696 A137697 * A137699 A137700 A137701 KEYWORD easy,nonn AUTHOR Leroy Quet, Feb 06 2008 EXTENSIONS More terms from Sean A. Irvine, Feb 12 2012 STATUS approved

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Last modified October 20 16:06 EDT 2018. Contains 316390 sequences. (Running on oeis4.)