This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.
%I A267943 #13 Sep 08 2022 08:46:15 %S A267943 3,4,6,94 %N A267943 Numbers n such that 2^n - 3 and 3*2^n - 1 are both prime. %C A267943 The intersection of A002235 and A050414 is not empty (3 does not belong to A267985). %F A267943 A002235 INTERSECT A050414. %e A267943 a(3) = 6 because 2^6 - 3 = 61 and 3*2^6 - 1 = 191 are both prime. %o A267943 (Magma) [n: n in [2..94] | IsPrime(2^n-3) and IsPrime(3*2^n-1)]; %o A267943 (PARI) isok(n) = isprime(2^n-3) && isprime(3*2^n-1); %Y A267943 Cf. A002235, A007505, A050414, A050415, A238694, A267985. %K A267943 nonn,hard,more %O A267943 1,1 %A A267943 _Arkadiusz Wesolowski_, Jan 22 2016