OFFSET
1,1
COMMENTS
3*5+4=19 prime, 5*7+6=41 prime, 29*31+30=929 prime, ...
LINKS
Harvey P. Dale, Table of n, a(n) for n = 1..1000
MATHEMATICA
lst={}; Do[p1=Prime[n]; p2=Prime[n+1]; If[p2-p1==2, a=p1*p2+(p1+1); If[PrimeQ[a], AppendTo[lst, p2]]], {n, 7!}]; lst
Transpose[Select[Select[Partition[Prime[Range[1600]], 2, 1], Last[#]- First[#] == 2&], PrimeQ[Times@@#+Mean[#]]&]][[2]] (* Harvey P. Dale, Jan 23 2012 *)
CROSSREFS
KEYWORD
nonn
AUTHOR
Vladimir Joseph Stephan Orlovsky, Dec 25 2008
STATUS
approved