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A250290
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Numbers k such that Euler(k) (A122045(k)) is a semiprime.
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0
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OFFSET
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1,1
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COMMENTS
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No more terms <= 200.
k=7634 is a term, but it is not known to be the next term after 78. - Jeppe Stig Nielsen, May 12 2023
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LINKS
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EXAMPLE
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a(2) = 10 so Euler(10) = 50521 = 19 * 2659 is a semiprime.
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PROG
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(PARI) is(k) = k%2==0 && bigomega(eulerfrac(k))==2 \\ slow, from Jeppe Stig Nielsen, May 12 2023
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CROSSREFS
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KEYWORD
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nonn,more
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AUTHOR
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STATUS
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approved
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