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A063685
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Numbers k such that !k + phi(k) - 1 is prime.
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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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LINKS
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MATHEMATICA
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n=1; Monitor[Parallelize[While[True, If[PrimeQ[Sum[Factorial[k], {k, 0, n-1}]+EulerPhi[n]-1], Print[n]]; n++]; n], n] (* J.W.L. (Jan) Eerland, Nov 19 2022 *)
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PROG
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(PARI) f(n) = sum(k=0, n-1, k!); \\ A003422
for(n=1, 10^6, if(isprime(f(n)+eulerphi(n)-1), print(n)))
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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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EXTENSIONS
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STATUS
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approved
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