Triangle read by rows: T(n,k) is the number of weighted lattice paths in B(n) having k returns to the horizontal axis (i.e., (1,-1)-steps ending on the horizontal axis). The members of B(n) are paths of weight n that start in (0,0), end on but never go below the horizontal axis, and whose steps are of the following four kinds: a (1,0)-step with weight 1; a (1,0)-step with weight 2; a (1,1)-step with weight 2; a (1,-1)-step with weight 1. The weight of a path is the sum of the weights of its steps.
A246179
Triangle read by rows: T(n,k) is the number of weighted lattice paths in B(n) having k returns to the horizontal axis (i.e., (1,-1)-steps ending on the horizontal axis). The members of B(n) are paths of weight n that start in (0,0), end on but never go below the horizontal axis, and whose steps are of the following four kinds: a (1,0)-step with weight 1; a (1,0)-step with weight 2; a (1,1)-step with weight 2; 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) =1a(2) =2a(3) =3a(4) =1a(5) =5a(6) =3a(7) =8a(8) =9a(9) =13a(10) =23a(11) =1a(12) =21a(13) =56a(14) =5a(15) =34a(16) =131a(17) =20a(18) =55a(19) =300a(20) =67a(21) =1a(22) =89a(23) =678a(24) =204a(25) =7a(26) =144a(27) =1523a(28) =581a(29) =35
External references
- oeis: A246179