OFFSET
1,1
COMMENTS
a(49) = 3^2224 - 2 and a(50) = 3^2521 - 2 are too big for a b-file. - Robert Israel, Nov 22 2015
LINKS
Robert Israel, Table of n, a(n) for n = 1..48
MAPLE
A:= NULL:
for k from 1 to 1000 do
t:= 3^k;
if isprime(t-2) then A:= A, t-2 fi;
if isprime(t+2) then A:= A, t+2 fi;
od:
A; # Robert Israel, Nov 22 2015
MATHEMATICA
Reap[For[k = 1, k <= 100, k++, p = 3^k-2; If[PrimeQ[p], Sow[p]]; If[PrimeQ[p+4], Sow[p+4]]]][[2, 1]] (* Jean-François Alcover, Dec 18 2013 *)
CROSSREFS
KEYWORD
nonn
AUTHOR
Reikku Kulon, Sep 15 2008
STATUS
approved