Number of walks within N^2 (the first quadrant of Z^2) starting and ending at (0,0) and consisting of n steps taken from {(-1, -1), (-1, 0), (-1, 1), (0, -1), (1, 0)}.
A151348
Number of walks within N^2 (the first quadrant of Z^2) starting and ending at (0,0) and consisting of n steps taken from {(-1, -1), (-1, 0), (-1, 1), (0, -1), (1, 0)}.
Terms
- a(0) =1a(1) =0a(2) =1a(3) =1a(4) =4a(5) =7a(6) =25a(7) =64a(8) =201a(9) =612a(10) =1961a(11) =6355a(12) =21026a(13) =70968a(14) =241810a(15) =837191a(16) =2925393a(17) =10334302a(18) =36813216a(19) =132242756a(20) =478470272a(21) =1742816732a(22) =6387201912a(23) =23539830561a(24) =87207544029a(25) =324627673245
External references
- oeis: A151348