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A181489
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Composite Flavius' numbers (A000960) whose prime factors are again Flavius' numbers.
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1
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27, 39, 49, 63, 91, 133, 147, 399, 567, 763, 2187, 13239, 15379, 15883, 21207, 32761, 151599, 173563, 180739, 268423, 746607, 2277163, 2557359, 3114783, 8218083, 28604419, 65002743, 68944959, 91727883, 93742347, 237963999, 310488507
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OFFSET
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1,1
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COMMENTS
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Contains A181488 as a subsequence.
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LINKS
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Klaus Brockhaus, Table of n, a(n) for n = 1..50
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PROG
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(PARI) A181489(Nmax) = { my(S=[]); for(n=2, Nmax, my(F=n); for(i=1, n-1, F=(n-i)*ceil(F/(n-i)+1)); S=setunion(S, Set(F)); isprime(F) & next; for(i=1, #F=factor(F)~, setsearch(S, F[1, i])|next(2)); print1(factorback(F~), ", "))}
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CROSSREFS
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Sequence in context: A159259 A097228 A039614 * A117103 A217008 A124940
Adjacent sequences: A181486 A181487 A181488 * A181490 A181491 A181492
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KEYWORD
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nonn
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AUTHOR
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M. F. Hasler, Oct 29 2010
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EXTENSIONS
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a(22)-a(32) from Donovan Johnson and Klaus Brockhaus, Oct 30 2010
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STATUS
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approved
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