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%I #12 Feb 13 2018 12:59:31
%S 1,3,4,8,1296,32,46656,128,256,512,1024,362797056,4096,8192,16384,
%T 32768,65536,131072,262144,524288,1048576,2097152,4194304,8388608,
%U 16777216,33554432,67108864,134217728,268435456,536870912,1073741824,2147483648
%N Sigma(A180162(n)), where A180162(n) is the smallest N such that sigma(N) is an n-th power, or 0 if no such N can be found.
%H Ray Chandler, <a href="/A180169/b180169.txt">Table of n, a(n) for n = 0..469</a>
%F Empirical o.g.f.: (-1-1*x+2*x^2-1280*x^4+2560*x^5-46592*x^6+93184*x^7-362795008*x^11+725590016*x^12)/(2*x-1). - Simon Plouffe, Feb. 26 2011.
%e A180162(4)=510 and so A180169(4)=sigma(510)=2^4*3^4.
%Y Cf. A065496, A000203, A180162.
%K easy,nonn
%O 0,2
%A _Walter Kehowski_, Aug 14 2010
%E a(23) onwards from _Ray Chandler_, Aug 20 2010
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