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%I #10 Jul 31 2015 02:52:28
%S 1,1,1,2,1,6,1,8,4,18,1,60,1,66,20,128,1,600,1,612,68,1026,1,6000,16,
%T 4098,256,8580,1,95226,1,32768
%N Number of subsets of the n-th roots of unity that sum to 1.
%F For prime p, a(p^i) = 2^(p^(i-1)-1).
%t << DiscreteMath`Combinatorica`; f[n_] := Plus @@ Table[ Count[ KSubsets[ Range[n], k], q_List /; Chop[ -1 + Plus @@ (E^((2.*Pi*I*q)/n))] === 0], {k, 0, n}]; Table[ f[n], {n, 24}] (* _Robert G. Wilson v_, Jun 03 2005 *)
%Y Cf. A103314 (number of subsets of the n-th roots of unity summing to zero) and A108417 (number of subsets of the n-th roots of unity summing to the absolute value of 1).
%K nonn,more
%O 1,4
%A _T. D. Noe_, May 23 2005
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