Problem #120
Balance the Weight
You are given a beam balance and N objects where i^{th} object weighs 2^{i-1} , 0 < i<=N. F(N) denotes the no. of ways of placing these objects(one by one) on balance such that the left side is always heavy (after every placement). Find the value of F(100) and give the answer modulo 10^9 + 7.