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 A175128 #2 Mar 30 2012 19:00:23
%S A175128 1,1,2,1,1,2,1,1,2,2,1,2,1,1,2,1,1,2,1,1,2,1,1,2,2,1,2,1,1,3
%N A175128 a(n) = the number of natural numbers m with n steps of iterations of {r - (smallest prime divisor of r)} needed to reach 0 starting at r = m .
%C A175128 See A055843, A175126 and A175127.
%e A175128 Example (a(7)=2): There are two natural numbers 14 and 15 with 7 steps in this iteration. 14-2=12, 12-2=10, 10-2=8, 8-2=6, 6-2=4, 4-2=2, 2-2=0; 15-3=12, 12-2=10, 10-2=8, 8-2=6, 6-2=4, 4-2=2, 2-2=0.
%K A175128 nonn
%O A175128 2,3
%A A175128 _Jaroslav Krizek_, Feb 15 2010