Evaluate the sum 1/3 + 2/3^2 + 4/3^3 + 8/3^4 + ...
= 1.
listfor(n, 0,100, (2^n)/3^(n+1))==(1 / 3, 2 / 9, 4 / 27, 8 / 81, 16 / 243, 32 / 729, 64 / 2187, 128 / 6561, 256 / 19683, 512 / 59049, 1024 / 177147......etc.)==converges to 1
