21-bit converter — tunable subtract, shows its work

Start at 2 or 3 (bit 0), then ×2 (bit 0) or ×2−1 (bit 1) for the other 20 bits, then subtract the amount below. The value before subtracting always lands in [1,048,577 , 3,145,728].

Bits (exactly 21)

Subtract at end

Default 1,572,864 = 50% more than 1,048,576 (2²⁰). Change it to explore.

Run random trials (count)