a = {3, 6, 10, 13, 16, 19, 22, 25, 28, 32, 35, 38, 41, 44, 50, 53, 56,
60, 63, 66};
A = Table[
FindRoot[0.1 == (-0.1 x Cos[x] + Sin[x])/(-0.1 x^2 Sin[x] -
x Cos[x]), {x, a[[i]]}], {i, 20}]