The submissions stack has been unacceptably high for several months now. Please voluntarily restrict your submissions and please help with the editing. (We don't want to have to impose further limits.)
A178244
Number of distinct transpositions of binary digits (0s and 1s) in n.
a(0)=1 because 0 (or 0 written in base 2), a(1)=1 because 1 (or 1 written in base 2), a(3)= 2 (or 10 written in base 2) and (01,10)=distinct transpositions.