%I A001074
%S A001074 1,4,7,8,9,13,19,25,27,28,31,32,36,37,43,49,52,56,61,63,64,67,72,73,76,
%T A001074 79,91,97,100,103,104,108,109,117,121,124,125,127,133,139,148,151,152,
%U A001074 157,163,169,171,172,175,181,189,193,196,199,200,211,216,217,223,224
%N A001074 Numbers n such that Sum_{k=0..n-1} exp(2*Pi*i*k^3/n) != 0.
%C A001074 Mark n points around horizontal disk with labels 0..n-1; place coins 
               at positions k^3 mod n for k=0..n-1; sequence gives n's for which 
               disk does not balance.
%e A001074 8 is in sequence because 4 coins go at 0, 1 each at 1, 3, 5, 7, so disk 
               is unbalanced in direction of point 0. 12 is not in sequence because 
               there are 2 coins at 0, 4, 8; 1 coin at 1, 3, 5, 7, 9, 11, so disk 
               balanced.
%Y A001074 Sequence in context: A047538 A074231 A076680 this_sequence A026316 A091158 
               A084791
%Y A001074 Adjacent sequences: A001071 A001072 A001073 this_sequence A001075 A001076 
               A001077
%K A001074 nice,nonn,easy
%O A001074 1,2
%A A001074 R. Lozyniak, (11(AT)onna.com)