cp's OEIS Frontend

A128657 Numbers k such that p(k+1)# - p(k)# - 1 is prime where p(i)# = product of first i primes = A002110(i).

%I A128657 #11 Oct 07 2024 00:48:14
%S A128657 1,2,3,4,8,24,35,56,79,132,281,342,631,1350,4929,5952,8128
%N A128657 Numbers k such that p(k+1)# - p(k)# - 1 is prime where p(i)# = product of first i primes = A002110(i).
%o A128657 (PARI) isok(n) = {my(pp=prod(k=1, n, prime(k))); isprime(pp*prime(n+1) - pp -1);} \\ _Michel Marcus_, Sep 20 2019
%Y A128657 Cf. A002110, A128420, A128421, A128658, A128659, A128660, A128661, A128662.
%K A128657 nonn,more
%O A128657 1,2
%A A128657 _Pierre CAMI_, Mar 19 2007
%E A128657 a(17) from _Michael S. Branicky_, Oct 06 2024