OFFSET
3,1
EXAMPLE
43*prime(4)#/6-6 = 43*2*3*5*7/6-6 = 1499, 43*prime(4)#/6+6 = 43*2*3*5*7/6+6 = 1511, 1499 and 1511 are consecutive primes with gap of 12, so a(4) = 43.
MATHEMATICA
a[n_] := Module[{k = 1, p = Product[Prime[i], {i, 1, n}]}, While[!(PrimeQ[k*p/6-6] && NextPrime[k*p/6-6] == k*p/6+6), k++]; k]; Array[a, 60, 3] (* Amiram Eldar, Jul 17 2021 *)
CROSSREFS
KEYWORD
nonn
AUTHOR
Pierre CAMI, Sep 11 2004
STATUS
approved