b5 = b3 * k^2
176 = 44 * k^2
k^2 = 4
k = 2
b1 = b3 : k^2 = 44 : 4 = 11
S5 = 11(1-2^5) : (1-2) = -341 : (-1) = 341
b5 = b3 * k^2
176 = 44 * k^2
k^2 = 4
k = 2
b1 = b3 : k^2 = 44 : 4 = 11
S5 = 11(1-2^5) : (1-2) = -341 : (-1) = 341