Reply To: Shabbos Locks

I can only try-

Yup, I noticed.

# of buttons in Combination	# of ways

0	                        1

1	                        13

2	                        78

3	                        286

4	                        715

5	                        1,287

6	                        1,716

7	                        1,716

8	                        1,287

9	                        715

10	                        286

11	                        78

12	                        13

13	                        1

Total	                        8,192

As we all know 2^13 is 8,192.