1=2^0
3=1+2=2^0+2^1,
7=3+4=3+2^2=2^0+2^1+2^2,
15=7+8=7+2^3=2^0+2^1+2^2+2^3,
31=15+16=2^0+2^1+2^2+2^3+2^4,
1=2^0
3=1+2=2^0+2^1,
7=3+4=3+2^2=2^0+2^1+2^2,
15=7+8=7+2^3=2^0+2^1+2^2+2^3,
31=15+16=2^0+2^1+2^2+2^3+2^4,