OFFSET
1,1
EXAMPLE
MATHEMATICA
a253027[n_] :=
Block[{k, t = Select[Prime[Range[n]], PrimeQ[2^# - 1] &], l},
l = Length[t];
Table[k = 3; While[! PrimeQ[k*2^t[[i]] + 1], k = k + 2]; k, {i, l}]]; a253027[600] (* Michael De Vlieger, Dec 26 2014 *)
PROG
(PFGW)
Command pfgw64 -f -e1000000 in.txt
in.txt file :
ABC2 a$*2^756839+$b // {number_primes, $b, 1}
b: from 1 to 1
a: from 1 to 1000000
(PARI) lista(nn) = {forprime (n=1, nn, if (isprime(2^n-1), k=3; while (!isprime(k*2^n+1), k += 2); print1(k, ", "); ); ); } \\ Michel Marcus, Dec 27 2014
CROSSREFS
KEYWORD
nonn,more
AUTHOR
Pierre CAMI, Dec 26 2014
EXTENSIONS
a(33)-a(35) from Pierre CAMI, Apr 06 2015
STATUS
approved