|
|
A118068
|
|
Numbers k such that A103557(k)*((prime(k)#)^2) - 1 is a Sophie Germain prime, where prime(k)# is the k-th primorial.
|
|
0
|
|
|
|
OFFSET
|
1,2
|
|
COMMENTS
|
|
|
LINKS
|
|
|
MATHEMATICA
|
q[n_] := Module[{p2 = Product[Prime[i], {i, 1, n}]^2, k=1}, While[!PrimeQ[k*p2-1] || !PrimeQ[k*p2+1], k++]; PrimeQ[2*k*p2 - 1]]; Select[Range[100], q] (* Amiram Eldar, Sep 11 2021 *)
|
|
CROSSREFS
|
|
|
KEYWORD
|
nonn,hard,more
|
|
AUTHOR
|
|
|
EXTENSIONS
|
|
|
STATUS
|
approved
|
|
|
|