so, something like:

a6 - b2 - c4 - d3 - e2 - f1

f5 - a4 - b3 - c2 - d1 - e6

e4 - f3 - a2 - b1 - c6 - d5

d3 - e2 - f1 - a6 - b5 - c4

c2 - d1 - e6 - f5 - a4 - b3

b1 - c6 - d5 - e4 - f3 - a2

?

Close. Pretty sure you have to use all values for letter and number combination. For example, you don't have f2.

You have two 2s in the second column

ok thank you. after studying he article again it gets clear.