OFFSET
1,1
COMMENTS
For all i, if i<n+2 then GCD(p_i,A111392(n))=1, where p_i is i-th prime.
A111392: a(n) = Product_{i=1..n-1} (Product_{k=1..i} p_k + Product_{k=i+1..n} p_k). - Robert G. Wilson v, Dec 22 2005
MATHEMATICA
f[n_] := Product[(Product[Prime[k], {k, i}] + Product[Prime[k], {k, i + 1, n}]), {i, n - 1}]; f[1] = 2; g[n_] := Block[{k = 1}, While[Mod[f[n], Prime[k]] != 0, k++ ]; Prime@k]; Array[g, 20] (* Robert G. Wilson v *)
CROSSREFS
KEYWORD
nonn
AUTHOR
Yasutoshi Kohmoto, Dec 15 2005
EXTENSIONS
More terms from Robert G. Wilson v, Dec 22 2005
STATUS
approved