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 A256864 #6 Jul 22 2020 11:39:24 %S A256864 3,7,13,19,31,41,43,61,71,83,103,109,131,137,139,151,157,167,179,193, %T A256864 197,199,223,229,241,257,271,281,283,311,337,349,383,421,433,439,461, %U A256864 463,487,503,523,547,571 %N A256864 Primes not occurring in A084721. %C A256864 Complement of the range of A084721 within the primes A000040. %o A256864 (PARI) N=300; setminus(primes(primepi(A083569(N)+N)),Set(vector(N,n,A083569(n)+n))) \\ _M. F. Hasler_, Apr 11 2015 %Y A256864 Cf. A083569, A084721. %K A256864 nonn %O A256864 1,1 %A A256864 _M. F. Hasler_, Apr 11 2015