Number of weighted lattice paths in L_n having no (1,0)-steps at level 0. The members of L_n are paths of weight n that start at (0,0), end on the horizontal axis and whose steps are of the following four kinds: an (1,0)-step with weight 1, an (1,0)-step with weight 2, a (1,1)-step with weight 2, and a (1,-1)-step with weight 1. The weight of a path is the sum of the weights of its steps.
A182889
Number of weighted lattice paths in L_n having no (1,0)-steps at level 0. The members of L_n are paths of weight n that start at (0,0), end on the horizontal axis and whose steps are of the following four kinds: an (1,0)-step with weight 1, an (1,0)-step with weight 2, a (1,1)-step with weight 2, and a (1,-1)-step with weight 1. The weight of a path is the sum of the weights of its steps.
Terms
- a(0) =1a(1) =0a(2) =1a(3) =2a(4) =3a(5) =8a(6) =17a(7) =38a(8) =89a(9) =206a(10) =485a(11) =1152a(12) =2751a(13) =6614a(14) =15983a(15) =38798a(16) =94569a(17) =231342a(18) =567771a(19) =1397562a(20) =3449285a(21) =8533886a(22) =21161001a(23) =52579900a(24) =130896887a(25) =326440746a(26) =815437967a(27) =2040049514a(28) =5111051473a(29) =12822135138
External references
- oeis: A182889