OFFSET
1,3
LINKS
R. Gerbicz, PolySieve program at UTM Prime Pages.
Mersenneforum, k.Mp +/- 1 discussion thread.
EXAMPLE
7*6*(2^5-1)-1=1301 prime, 1301 and 1303 twin primes so K(3)=7 as M(3)=2^5-1.
MATHEMATICA
Array[Block[{k = 1, m = 2^MersennePrimeExponent@ # - 1}, While[! AllTrue[6 k m + {-1, 1}, PrimeQ], k++]; k] &, 14] (* Michael De Vlieger, Dec 22 2019 *)
PROG
(PARI) forprime(p=2, 607, if(isprime(Mp=2^p-1), forstep(k=6, 10^9, 6, if(isprime(k*Mp-1), if(isprime(k*Mp+1), print1(k/6", "); break))))) \\ Serge Batalov, Dec 22 2019
CROSSREFS
KEYWORD
nonn,more
AUTHOR
Pierre CAMI, Feb 08 2007
EXTENSIONS
Missing term 44649 and a(26-28) from Serge Batalov, Dec 21 2019
STATUS
approved