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%I #26 May 04 2018 05:42:30
%S 1,2,3,6,11,15,17,19,22,51,867,1909,9641
%N Numbers k such that k!+1 reversed is a prime.
%C a(14) > 19200, if it exists. - _Giovanni Resta_, May 04 2018
%t Do[If[PrimeQ[FromDigits[Reverse[IntegerDigits[n! + 1]]]], Print[n]], {n, 400}] (* _Vincenzo Librandi_, Jan 25 2018 *)
%o (PARI) isok(n) = isprime(fromdigits(Vecrev(digits(n!+1)))); \\ _Michel Marcus_, Jan 26 2018
%Y Cf. A002981.
%K nonn,base,more
%O 1,2
%A _Paolo Galliani_, Jan 25 2018
%E a(1)-a(3) and a(8)-a(10) from _Vincenzo Librandi_, Jan 25 2018
%E a(11)-a(12) from _Paolo Galliani_, May 02 2018
%E a(13) from _Giovanni Resta_, May 04 2018
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