Number of North-East lattice paths from (0,0) to (n,n) that cross the diagonal y = x horizontally exactly three times.
A268446
Number of North-East lattice paths from (0,0) to (n,n) that cross the diagonal y = x horizontally exactly three times.
Terms
- a(0) =1a(1) =14a(2) =119a(3) =798a(4) =4655a(5) =24794a(6) =123970a(7) =592020a(8) =2731365a(9) =12271350a(10) =53993940a(11) =233646504a(12) =997490844a(13) =4211628008a(14) =17620076360a(15) =73153696336a(16) =301758997386
External references
- oeis: A268446