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 A366550 #28 Oct 15 2023 22:03:05 %S A366550 2,6,18,54,564,3512,6542,564163,2063689,54400028,5586502348, %T A366550 252252704148404,971269945245201,3745011184713964 %N A366550 Numbers k such that bitwise AND of prime(k) and prime(k+1) = 1. %C A366550 Suggested by a comment by _Alex Ratushnyak_ in A175330. %F A366550 a(n) = A007053(A214415(n-1)). %e A366550 18 is a term since prime(18) AND prime(19) = 1, %e A366550 prime(18) = 61 = binary 0111101 %e A366550 prime(19) = 67 = binary 1000011 %e A366550 bitwise AND = 0000001 %t A366550 A366550list[upto_]:=PrimePi[Select[2^Range[upto],BitAnd[NextPrime[#],NextPrime[#,-1]]==1&]]; %t A366550 A366550list[37] (* Uses formula, considering values in A214415 up to 37 *) %o A366550 (PARI) isok(k) = bitand(prime(k), prime(k+1)) == 1; \\ _Michel Marcus_, Oct 14 2023 %Y A366550 Positions of ones in A175330. %Y A366550 Cf. A007053, A214415. %K A366550 nonn,base,hard,more %O A366550 1,1 %A A366550 _Paolo Xausa_, Oct 13 2023