Hello Thank you for commenting......I know this interpretation of lattice paths, But my question is how is this generalization can be used for this question?
To find the ways without touching the diagonal is = 2nCn - 2nCn-1 where 2nCn-1 is the violating paths right??
so to find the answer for the sequence question we have to take all the length 2n strings with an equal number of 1’s and 0’s which is = 2nCn. But the answer is = 2nCn - 2nCn-1. we know for the lattice path problem that (2nCn-1) is the no of violating paths. but what is this (2nCn-1) for this particular question??