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%I #8 Mar 30 2012 18:39:15
%S 1,2,3,7,12,16,21,26,40,73,106,139,172,205,238,271,417,516,549,893,
%T 1237,1581,1958,2302,3023,3367,4088,10822,20407,25732,26797,78261,
%U 182254,338776,442769,599291,859806,1120321,1380836,2318903,4559545,6279157
%N Least positive integer multiples of angle x such that their direction cosines form a unit vector: sum(k>0, cos(a(k)*x)^2)=1, where a(1)=1 and x=(2/3).
%o (PARI) x=(2/3); z=cos(x)^2; a=1; for(n=1,45,b=a+1; while(z+cos(b*x)^2>1,b++); z=z+cos (b*x)^2; a=b; print1(b,","))
%Y Cf. A080136, A080137, A080138, A080139.
%K nonn
%O 1,2
%A _Paul D. Hanna_, Jan 30 2003
%E Extended with PARI program by _Benoit Cloitre_, Feb 04 2003