For n <= 1 there are no 2-small-step numbers in the interval 2^n until 2^(n+1).


For 2 <= n <= 6 there are

      (1,4,9,17,27)_n

many 2-small-step numbers in the interval 2^n until 2^(n+1).


For any n >= 7 there are

     n^2-n-2

many 2-small-step numbers in the interval  2^n until 2^(n+1). 



For 2 <= n <= 5 there are  (1,5,14,31)_n  many 2-small-step numbers < 2^(n+1).

and for any n >= 6 there are  (n^3-7n)/3  many 2-small-step numbers < 2^(n+1).