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 A158915 #2 Mar 30 2012 17:22:54 %S A158915 2,6,6,184926 %N A158915 Least number k such that there is an m > k with sigma_n(k) = sigma_n(m). %C A158915 It is easy to verify the first three terms using sequences A000005, A000203, and A001157. The first term of A131908 gives a(3). The a(4) term is greater than 10^8. Does a(n) exist for all n? %e A158915 sigma_0(2)=sigma_0(3); sigma_1(6)=sigma_1(12); sigma_2(6)=sigma_2(7); sigma_3(184926)=sigma_3(194315). %K A158915 more,nonn %O A158915 0,1 %A A158915 _T. D. Noe_, Mar 30 2009