Number of paths from (0,0) to (n,3), with vertices (i,k) satisfying 0 <= k <= 3, consisting of segments given by the vectors (1,1), (1,2), (1,-1).
A247326
Number of paths from (0,0) to (n,3), with vertices (i,k) satisfying 0 <= k <= 3, consisting of segments given by the vectors (1,1), (1,2), (1,-1).
Terms
- a(0) =0a(1) =0a(2) =2a(3) =2a(4) =6a(5) =10a(6) =20a(7) =40a(8) =74a(9) =150a(10) =282a(11) =558a(12) =1072a(13) =2088a(14) =4050a(15) =7850a(16) =15254a(17) =29562a(18) =57412a(19) =111344a(20) =216106a(21) =419294a(22) =813594a(23) =1578750a(24) =3063264a(25) =5944144a(26) =11533698a(27) =22380210a(28) =43426118a(29) =84263882
External references
- oeis: A247326