The three digits in the yellow colored pattern, combined with the six digits in the blue pattern, must be filled with the numbers  from 1 to 9. This also applies to other patterns (gray, red, etc.). This patterns must always be combined with the yellow pattern.

 

 

Download the Sudokus with double patterns:

 

A. Double patterns I:

1. ** moderate 
2. *** difficult
3. ***** extreem difficult

B. Double patterns II:

1. ** moderate 
2. *** difficult
3. **** very difficult

 

C. Double patterns III:

1. ** moderate
2. **** zeer moeilijk
3. ***** extreme difficult

 

D. Double patterns with 5 blocks:

1. *** moeilijk

 

E. Double patterns with 8 blocks:

1. *** difficult

 

F. Double patterns with 12 blocks:

1. *** difficult