b_1 = 7/4
b_5 = 7/64
b_(n+3) = 7/(2^(n+4))
b_(3n) = 7 / (2^(3n+1))
b1 = 7/4b5 = 7/64b(n+3) = 7/(2^(n+4))b(3n) = 7 / (2^(3n+1))
