1) Given a number 1 to 5, get a new one if it's 5, else throw away the MSB, you get 2 bits of randomness per number. Subtract one and call it a. (Now you have

1) Given a number 1 to 5, get a new one if it's 5, else throw away the MSB, you get 2 bits of randomness per number. Subtract one and call it a. (Now you have two bits of randomness evenly distributed among the set {00, 01, 10, 11}) 2) Get another number 1 to 5, toss it if it's 5, take the LSB. Call it b. (Now you have another bit of randomness, evenly distributed among {0,1}) 3) if b == 1 and a == 11, start over. else return (4b)+a+1 Python implementation (with the -1 then +1 factored out): def one_to_seven(debug=False): a = one_to_five() while a == 5: a = one_to_five() b = one_to_five() while b == 5: b = one_to_five() b = (b % 2) * 4 if a+b == 8: return one_to_seven() return a+b