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A303937
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Numbers k such that k!-1 reversed is a 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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EXAMPLE
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5 is in the sequence because 5!-1 reversed is 911, which is prime.
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MATHEMATICA
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ParallelTable[If[PrimeQ[IntegerReverse[Factorial[k]-1]], k, Nothing], {k, 1, 5703}]//.{}->Nothing (* J.W.L. (Jan) Eerland, Aug 08 2022 *)
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PROG
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(PARI) isok(n) = isprime(fromdigits(Vecrev(digits(n!-1))));
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CROSSREFS
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KEYWORD
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nonn,base,more
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AUTHOR
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STATUS
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approved
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