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Numbers k such that p(k+1)# - p(k)# - 1 is prime where p(i)# = product of first i primes = A002110(i).
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%I #11 Oct 07 2024 00:48:14

%S 1,2,3,4,8,24,35,56,79,132,281,342,631,1350,4929,5952,8128

%N Numbers k such that p(k+1)# - p(k)# - 1 is prime where p(i)# = product of first i primes = A002110(i).

%o (PARI) isok(n) = {my(pp=prod(k=1, n, prime(k))); isprime(pp*prime(n+1) - pp -1);} \\ _Michel Marcus_, Sep 20 2019

%Y Cf. A002110, A128420, A128421, A128658, A128659, A128660, A128661, A128662.

%K nonn,more

%O 1,2

%A _Pierre CAMI_, Mar 19 2007

%E a(17) from _Michael S. Branicky_, Oct 06 2024