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 A105467 #6 Mar 05 2019 10:26:35
%S A105467 0,0,5,22,91,286,863,2577,7717,23160,69939,209485,627826,1881554,
%T A105467 5645226,16936048
%N A105467 Number of irregular primes less than or equal to the 3^n-th prime.
%C A105467 Limit_{n->inf.} a(n)/3^n = 1-e^(-1/2).
%t A105467 ip={ the list of irregular primes to 12 million }; Table[ Length[ Select[ip, # < Prime[3^n] &]], {n, 9}]
%Y A105467 Cf. A038833, A105458, A105462.
%K A105467 hard,nonn,more
%O A105467 1,3
%A A105467 _Robert G. Wilson v_, Apr 07 2005
%E A105467 Terms corrected and a(10)-a(16) added by _Amiram Eldar_, Mar 05 2019