2^1•[2+2^6:(4^2+4^4:4^2)]=
2•[2+2^6:(4^2+4^2)]=
2•[2+2^6:(4^2×2)]
2•[2+2^6:(2^2)^2×2]=
2•(2+2^6:2^4×2)=
2•(2+2^2×2)=
2•(2+8)=
2•10=
20