Number of nX3 nonnegative integer arrays with upper left 0 and lower right n+3-4 and value increasing by 0 or 1 with every step right or down.

A252871

Number of nX3 nonnegative integer arrays with upper left 0 and lower right n+3-4 and value increasing by 0 or 1 with every step right or down.

Terms

    a(0) =1a(1) =8a(2) =44a(3) =153a(4) =413a(5) =949a(6) =1948a(7) =3676a(8) =6497a(9) =10894a(10) =17492a(11) =27083a(12) =40653a(13) =59411a(14) =84820a(15) =118630a(16) =162913a(17) =220100a(18) =293020a(19) =384941a(20) =499613a(21) =641313a(22) =814892a(23) =1025824a(24) =1280257a(25) =1585066a(26) =1947908a(27) =2377279a(28) =2882573a(29) =3474143

External references