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A086565
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Smallest k such that (10^k - 1)/9 has n distinct prime divisors. Or a(n)= smallest value of k such that A000042(k) has exactly n distinct prime divisors.
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1
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1, 2, 3, 9, 8, 6, 15, 12, 18, 45, 24, 32, 54, 30, 42, 64, 102, 72, 108, 154, 60, 84, 96, 140, 126, 200, 120, 204, 308, 168, 192, 280, 180, 210, 240, 252, 330
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OFFSET
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0,2
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COMMENTS
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a(40) = 300; all other subsequent terms are > 322. - Ray Chandler, Apr 23 2017
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LINKS
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PROG
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(PARI) a(n) = my(k=1); while(omega((10^k - 1)/9) !=n, k++); k; \\ Michel Marcus, Apr 23 2017
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CROSSREFS
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KEYWORD
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more,nonn
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AUTHOR
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EXTENSIONS
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STATUS
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approved
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