login
Numbers k such that both 137*k + 139 and 139*k + 137 are primes.
1

%I #16 Feb 09 2020 12:02:44

%S 0,20,54,66,104,140,194,204,210,260,264,276,360,390,546,570,600,794,

%T 836,846,860,986,1086,1140,1146,1160,1254,1260,1284,1296,1350,1436,

%U 1440,1454,1506,1650,1706,1736,1770,1814,1826,1860,1904,1970

%N Numbers k such that both 137*k + 139 and 139*k + 137 are primes.

%C Intersection of A108027 and A108028.

%H Daniel Starodubtsev, <a href="/A108108/b108108.txt">Table of n, a(n) for n = 1..10000</a>

%t s={};Do[If[PrimeQ[137*n+139]&&PrimeQ[139*n+137], s=Append[s, n]], {n, 2000}];s

%Y Cf. A108027, A108028.

%K nonn

%O 1,2

%A _Zak Seidov_, Jun 03 2005