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), (1, 0, 1)}.

A148769

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), (1, 0, 1)}.

Terms

    a(0) =1a(1) =1a(2) =3a(3) =8a(4) =21a(5) =68a(6) =214a(7) =677a(8) =2273a(9) =7647a(10) =25918a(11) =89348a(12) =311027a(13) =1088056a(14) =3829653a(15) =13588462a(16) =48394968a(17) =172944341a(18) =621204971a(19) =2238314211a(20) =8085624821a(21) =29299373131a(22) =106444414667a(23) =387514343973

External references