%I #4 Jun 12 2020 00:08:30
%S 4,1,5,8,5,5,5,9,6,7,8,9,8,6,7,9,8,8,7,8,8,0,0,4,8,0,1,9,8,2,9,3,9,0,
%T 1,9,0,4,2,5,8,6,4,7,0,3,9,3,3,9,7,7,2,2,7,6,0,8,9,5,8,3,0,1,9,0,3,1,
%U 1,7,7,4,1,2,9,7,7,8,4,5,2,3,5,7,3,2
%N Decimal expansion of the number u such that the line normal to the graph of y = sin x at (u, sin u) passes through (Pi/4,0).
%e u = 0.4158555967898679887880048019...
%t u = u /. FindRoot[0 == (-Pi/4) Sec[u] + u Sec[u] + Sin[u], {u, 0}, WorkingPrecision -> 150]
%t RealDigits[u][[1]]
%Y Cf. A332500, A332507.
%K nonn,cons
%O 0,1
%A _Clark Kimberling_, May 05 2020