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 A105458 #5 Mar 05 2019 08:37:01
%S A105458 0,0,0,3,9,48,131,334,880,2355,6341,17157,47620,132015,366790,1025835,
%T A105458 2884928,8143498
%N A105458 Number of irregular primes less than 3^n.
%t A105458 ip={ the list of irregular primes to 12 million }; Table[ Length[ Select[ip, # < 3^n &]], {n, 14}]
%Y A105458 Cf. A055729, A105462, A105467.
%K A105458 hard,nonn,more
%O A105458 1,4
%A A105458 _Robert G. Wilson v_, Apr 07 2005
%E A105458 a(15)-a(18) from _Amiram Eldar_, Mar 05 2019