OFFSET
1,1
LINKS
Pierre CAMI, Table of n, a(n) for n = 1..300
Pierre CAMI, Program
EXAMPLE
q=2*339*3^4-1=54917 prime, 3=prime(2),
r=2*339*54917^4-1=6166758091711727821637 prime,
s=2*339*6166758091711727821637^4-1 = 980522001959784653177131336948216283558445362942309523305624291540914216062705919811218757 prime,
so a(2)=339 with b=-1 c=-1 d=-1.
PROG
See link.
CROSSREFS
KEYWORD
nonn,less
AUTHOR
Pierre CAMI, Apr 26 2013
STATUS
approved