Triangle read by rows: T(n,k) is number of paths from (0,0) to (3n,0) that stay in the first quadrant (but may touch the horizontal axis), consisting of steps u=(2,1), U=(1,2), or d=(1,-1) and having height of the first peak equal to k.
A108437
Triangle read by rows: T(n,k) is number of paths from (0,0) to (3n,0) that stay in the first quadrant (but may touch the horizontal axis), consisting of steps u=(2,1), U=(1,2), or d=(1,-1) and having height of the first peak equal to k.
Terms
- a(0) =1a(1) =1a(2) =2a(3) =5a(4) =2a(5) =1a(6) =10a(7) =28a(8) =13a(9) =11a(10) =3a(11) =1a(12) =66a(13) =196a(14) =90a(15) =89a(16) =34a(17) =18a(18) =4a(19) =1a(20) =498a(21) =1532a(22) =694a(23) =736a(24) =311a(25) =197a(26) =66a(27) =26a(28) =5a(29) =1
External references
- oeis: A108437