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 A259154 #7 Jun 19 2015 09:43:00
%S A259154 2,1,1,1,2,1,1,2,1,1,1,2,3,1,1,2,1,1,1,2,2,2,1,1,1,2,2,1,1,1,2,2,3,2,
%T A259154 1,2,1,2,1,1,1,3,1,1,3,1,1,1,1,2,1,1,2,3,2,2,2,1,2,1,1,2,2,1,2,1,1,2,
%U A259154 1,2,1,2,1,3,1,1,2,2,1,2,2,1,1,1,3,3,2,2,2,1,1,1,1,2,2,2,2,3,1,1,1,1,1,1,1,2
%N A259154 Number of values v whose pi-based arithmetic derivative equals n.
%C A259154 a(n) > 0 for all n >= 0.
%H A259154 Alois P. Heinz, <a href="/A259154/b259154.txt">Table of n, a(n) for n = 0..20000</a>
%F A259154 a(n) = |{ v >= 0 : A258851(v) = n }|.
%Y A259154 Row lengths of A259153.
%K A259154 nonn
%O A259154 0,1
%A A259154 _Alois P. Heinz_, Jun 19 2015