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, 0, 0), (0, 1, 1), (1, -1, 0), (1, 0, -1)}.
A148924
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, 0, 0), (0, 1, 1), (1, -1, 0), (1, 0, -1)}.
Terms
- a(0) =1a(1) =1a(2) =3a(3) =9a(4) =27a(5) =89a(6) =305a(7) =1059a(8) =3745a(9) =13479a(10) =49087a(11) =180213a(12) =666995a(13) =2486247a(14) =9317763a(15) =35090553a(16) =132721777a(17) =503845539a(18) =1919019473a(19) =7330426325a(20) =28075074671a(21) =107777969567a(22) =414624345139
External references
- oeis: A148924