Number of walks within N^2 (the first quadrant of Z^2) starting at (0,0), ending on the vertical axis and consisting of n steps taken from {(-1, -1), (0, -1), (0, 1), (1, 1)}.
A151396
Number of walks within N^2 (the first quadrant of Z^2) starting at (0,0), ending on the vertical axis and consisting of n steps taken from {(-1, -1), (0, -1), (0, 1), (1, 1)}.
Terms
- a(0) =1a(1) =1a(2) =3a(3) =6a(4) =21a(5) =52a(6) =193a(7) =532a(8) =2034a(9) =5985a(10) =23283a(11) =71610a(12) =281688a(13) =894660a(14) =3545919a(15) =11541114a(16) =45988056a(17) =152599174a(18) =610459630a(19) =2057627572a(20) =8255756937a(21) =28190598072a(22) =113365682625a(23) =391366771432
External references
- oeis: A151396