Number of n X 3 0..3 arrays with rows and antidiagonals unimodal and columns nondecreasing.

A223859

Number of n X 3 0..3 arrays with rows and antidiagonals unimodal and columns nondecreasing.

Terms

    a(0) =50a(1) =684a(2) =4884a(3) =24199a(4) =93731a(5) =303560a(6) =857696a(7) =2175884a(8) =5058530a(9) =10940664a(10) =22267210a(11) =43028893a(12) =79505879a(13) =141274716a(14) =242543322a(15) =403888650a(16) =654482250a(17) =1034900244a(18) =1600626232a(19) =2426368355a(20) =3611325155a(21) =5285548992a(22) =7617570604a(23) =10823463928

External references