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%I #2 Mar 30 2012 17:22:54
%S 2,6,6,184926
%N Least number k such that there is an m > k with sigma_n(k) = sigma_n(m).
%C 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 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 more,nonn
%O 0,1
%A _T. D. Noe_, Mar 30 2009