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A073411
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cototient(x) - 1 where x are the odd semiprimes (i.e., x are odd terms in A001358).
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1
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2, 6, 8, 4, 12, 10, 14, 6, 18, 14, 20, 16, 24, 16, 20, 30, 18, 32, 22, 38, 26, 22, 10, 42, 44, 24, 48, 22, 32, 34, 54, 28, 12, 60, 62, 40, 26, 68, 34, 44, 28, 72, 46, 36, 74, 28, 50, 80, 30, 84, 32, 42, 56, 90, 46, 16, 98, 62, 34, 48, 102, 64, 104, 38, 108, 34, 110, 52, 70
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OFFSET
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1,1
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COMMENTS
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If the Goldbach conjecture is true, all even numbers appear at least once in the sequence since pq - phi(pq) - 1 = p + q.
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LINKS
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FORMULA
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MATHEMATICA
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Map[# - EulerPhi@ # - 1 &, Select[Range[1, 335, 2], PrimeOmega # == 2 &]] (* Michael De Vlieger, Jul 30 2017 *)
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PROG
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(PARI) lista(nn) = forstep(n=1, nn, 2, if (bigomega(n)==2, print1(n-eulerphi(n)-1, ", "))); \\ Michel Marcus, Jul 30 2017
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CROSSREFS
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KEYWORD
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easy,nonn
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AUTHOR
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STATUS
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approved
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