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%I #15 Mar 05 2014 15:10:56
%S 1,0,0,10363,136647,3018141,66411009,1636922343,31276995183,
%T 688217286267,15200749439001,324029599659171,7264291502741679,
%U 160447401116572437,3530475812620849113,75514126111770824037,1662716417771040164631,36586320846189859358019,804905851136700392012493,17704604426749226872106319
%N a(n) is the smallest number m such that sigma(m)=22^n, or 0 if m does not exist.
%C Conjecture: Given any even integer E not a power of 2 (see A078426) there exists a positive integer N such that for all n>=N the equation sigma(m)=E^n has at least one solution for m.
%H Max Alekseyev, <a href="/A180460/b180460.txt">Table of n, a(n) for n = 0..100</a>
%e a(4)=136647=3^4*7*241 since sigma(3^4*7*241)=(11^2)(2^3)(2*11^2)=2^4*11^4 and 136647 is the smallest such number.
%Y Cf. A048251, A110077, A180265, A180461, A180462, A180463, A180464.
%K nonn
%O 0,4
%A _Walter Kehowski_, Sep 06 2010
%E Terms a(37) onward (in b-file) from _Max Alekseyev_, Mar 04 2014