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%I #14 Nov 27 2022 08:56:24
%S 1,2,3,4,21,93
%N Values of k such that prime(k)!+prime(k+1) is prime.
%C The primes of the form prime(n)!+prime(n+1) are in A094108.
%C If it exists, a(7) > 1397. - _J.W.L. (Jan) Eerland_, Nov 27 2022
%e 4 is in the sequence because prime(4)=7, prime(5)=11 and 7!+11=5051 is prime.
%p a:=proc(n) if isprime(ithprime(n)!+ithprime(n+1))=true then n else fi end: seq(a(n),n=1..50);
%t Select[Range[100],PrimeQ[Prime[#]!+Prime[#+1]]&] (* _Harvey P. Dale_, Jun 21 2021 *)
%o (PARI) isok(n) = isprime(prime(n)!+prime(n+1)); \\ _Michel Marcus_, Aug 20 2019
%Y Cf. A094108.
%K nonn,more
%O 1,2
%A _Emeric Deutsch_, Jun 24 2005
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