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 A261639 Values of n such that prime(n+1)!/prime(n) + 1 is a prime number. 0

%I #12 Aug 28 2015 18:07:28

%S 2,3,4,5,19,110

%N Values of n such that prime(n+1)!/prime(n) + 1 is a prime number.

%C a(1) = 2, a(2) = 3, a(3) = 4, a(4) = 5. It can be seen as a nice consecutiveness on sequence for first four items. Another point is that sequence of prime(n+1)! / prime(n) is observed in A260754.

%C a(7) > 2300. - _Giovanni Resta_, Aug 28 2015

%e For n=2 the (prime(n+1)! / prime(n)) + 1 = 41. 41 is prime.

%o (PARI) for(n=1, 1e3, if(isprime(k=((prime(n+1)!/prime(n))+1)), print1(n", ")))

%Y Cf. A260754.

%K nonn,more

%O 1,1

%A _Altug Alkan_, Aug 27 2015

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Last modified August 8 08:46 EDT 2024. Contains 375018 sequences. (Running on oeis4.)