Number T(n,k) of n-step walks on cubic lattice starting at (0,0,0), ending at (0,k,n-k), remaining in the first (nonnegative) octant and using steps (0,0,1), (0,1,0), (1,0,0), (-1,1,1), (1,-1,1), and (1,1,-1); triangle T(n,k), n>=0, 0<=k<=n, read by rows.
A328300
Number T(n,k) of n-step walks on cubic lattice starting at (0,0,0), ending at (0,k,n-k), remaining in the first (nonnegative) octant and using steps (0,0,1), (0,1,0), (1,0,0), (-1,1,1), (1,-1,1), and (1,1,-1); triangle T(n,k), n>=0, 0<=k<=n, read by rows.
Terms
- a(0) =1a(1) =1a(2) =1a(3) =1a(4) =3a(5) =1a(6) =1a(7) =7a(8) =7a(9) =1a(10) =1a(11) =15a(12) =26a(13) =15a(14) =1a(15) =1a(16) =31a(17) =82a(18) =82a(19) =31a(20) =1a(21) =1a(22) =63a(23) =237a(24) =343a(25) =237a(26) =63a(27) =1a(28) =1a(29) =127
External references
- oeis: A328300