%I #5 Mar 30 2012 18:57:55
%S 5,7,6,4,5,6,9,4,4,5,6,1,7,1,8,1,1,0,8,6,3,3,7,9,4,8,7,6,4,5,5,7,3,4,
%T 7,7,4,7,2,5,5,1,0,6,9,5,3,9,7,7,7,6,7,1,6,4,7,5,1,4,4,9,7,9,5,7,0,5,
%U 7,3,4,3,7,0,6,2,0,9,4,3,8,0,9,8,0,3,6,9,6,4,6,4,2,4,9,8,0,1,9
%N Decimal expansion of the least x>0 that gives the absolute minimum of sin(x)+sin(2x)+sin(3x)+sin(4x).
%C See A198677 for a guide to related sequences.
%e x=5.764569445617181108633794876455734774725510...
%e min=-3.232384871111452330884269520493428181450...
%t n = 4; f[t_] = Sin[t]; s[t_] := Sum[f[k*t], {k, 1, n}];
%t x = N[Minimize[s[t], t], 110]; u = Part[x, 1]
%t v = t /. Part[x, 2]
%t RealDigits[u] (* A198729 *)
%t RealDigits[v] (* A198730 *)
%t Plot[s[t], {t, -3 Pi, 3 Pi}]
%Y Cf. A198677.
%K nonn,cons
%O 1,1
%A _Clark Kimberling_, Oct 29 2011