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 A241945 #23 Jan 06 2019 12:34:02 %S A241945 2,3,6,17,27,30,48,53,57,68,94,137,138,143,156,157,248,259,269,289, %T A241945 296,316,360,369,402,425,429,430,432,446,474,500,522,580,596,631,656, %U A241945 760,777,810,828,875,906,951,994,1154,1163,1233,1273,1338,1346,1352,1378,1381,1385,1391,1402,1422,1436,1495,1552,1602 %N A241945 Indices n where both prime(n) + 2*prime(n+1) and 2*prime(n) + prime(n+1) are primes. %H A241945 Amiram Eldar and Zak Seidov, <a href="/A241945/b241945.txt">Table of n, a(n) for n = 1..10000</a> %e A241945 n=2 is in the sequence because 3 + 2*5 = 13 and 5 + 2*3 = 11 are primes. %e A241945 n=3 is in the sequence because 5 + 2*7 = 19 and 7 + 2*5 = 17 are primes. %e A241945 n=6 is in the sequence because 17 + 2*13 = 43 and 13 + 2*17 = 47 are primes. %o A241945 (PARI) isok(n) = my(p=prime(n), q=nextprime(p+1)); isprime(p+2*q) && isprime(2*p+q); \\ _Michel Marcus_, Jan 06 2019 %Y A241945 Cf. A094104 (primes of form 2*p + q), A094105 (primes of form p + 2*q). %Y A241945 Cf. A181848, A186169, A215684. %K A241945 nonn %O A241945 1,1 %A A241945 _Zak Seidov_, May 03 2014