Number of walks within N^3 (the first octant of Z^3) starting at (0,0,0) and consisting of n steps taken from {(-1, -1, 1), (-1, 0, 0), (0, 1, -1), (0, 1, 0), (1, 0, 0)}.
A149920
Number of walks within N^3 (the first octant of Z^3) starting at (0,0,0) and consisting of n steps taken from {(-1, -1, 1), (-1, 0, 0), (0, 1, -1), (0, 1, 0), (1, 0, 0)}.
Terms
- a(0) =1a(1) =2a(2) =5a(3) =15a(4) =47a(5) =157a(6) =556a(7) =2019a(8) =7584a(9) =29152a(10) =113984a(11) =453620a(12) =1829076a(13) =7459678a(14) =30755525a(15) =127897631a(16) =536170959a(17) =2264041183a(18) =9619849541a(19) =41113706454a(20) =176630946692a(21) =762409276043
External references
- oeis: A149920