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 A275081 #23 Oct 19 2018 11:15:51 %S A275081 3,13,31,43,67,71,83,89,107,151,157,163,191,197,199,227,283,293,307, %T A275081 311,347,359,373,401,409,431,439,443,467,479,523,557,563,569,587,599, %U A275081 601,631,653,677,683,719,761,787,827,839,877,881,883,911,919,929,947 %N A275081 Duplicate of A097443. %K A275081 dead %O A275081 1,1