Need a Work-around for OneHotEncoder Issue in SKLearn Preprocessing
Try the following approach:

In [51]: pd.get_dummies(b.astype(str), prefix_sep='')
Out[51]:
   018643548  056748  08511896  128614357  151001984  18511896  240084357  251001984  256748
0          0       1         0          0          0         1          0          1       0
1          1       0         0          1          0         0          0          0       1
2          0       0         1          0          1         0          1          0       0