Number of nX3 arrays containing 3 copies of 0..n-1 with rows and columns nondecreasing.

A265000

Number of nX3 arrays containing 3 copies of 0..n-1 with rows and columns nondecreasing.

Terms

    a(0) =1a(1) =2a(2) =7a(3) =29a(4) =140a(5) =758a(6) =4448a(7) =27782a(8) =182322a(9) =1245399a(10) =8793649a(11) =63844600a(12) =474662243a(13) =3601895485a(14) =27823860424a(15) =218325937188

External references