OFFSET
1,1
LINKS
Hugo Pfoertner, Table of n, a(n) for n = 1..10000
EXAMPLE
3 is in the sequence because [3,5] is a pair of twin primes and (3*5 - 1)/2=7 is prime.
MATHEMATICA
lst={}; d=2; Do[p1=Prime[n]; p2=Prime[n+1]; If[p2-p1==2&&PrimeQ[(p1*p2-1)/2], AppendTo[lst, p1]], {n, 10^3}]; lst (* Vladimir Joseph Stephan Orlovsky, Aug 08 2008 *)
CROSSREFS
KEYWORD
nonn
AUTHOR
Hugo Pfoertner, Jul 09 2005
STATUS
approved