OFFSET
0,1
COMMENTS
LINKS
Michael De Vlieger, Table of n, a(n) for n = 0..1000
EXAMPLE
n=50:3n+1=151,6n+2=302, a(50)=93923 prime with (93922-1)/302=311, prime and with 302.93923+1=28364747 prime; so the {311,93923,28364747} "generalized [short] Cunningham-chain" is defined.
MATHEMATICA
Table[Function[m, p = 2; While[Nand @@ PrimeQ@ {2 m p + 1, (p - 1)/(2 m)}, p = NextPrime@ p]; p][3 n + 1], {n, 0, 41}] (* Michael De Vlieger, May 15 2017 *)
CROSSREFS
KEYWORD
nonn
AUTHOR
Labos Elemer, Jul 22 2003
STATUS
approved