Number of 3Xn 0..3 arrays with rows and antidiagonals unimodal and columns nondecreasing.
A223866
Number of 3Xn 0..3 arrays with rows and antidiagonals unimodal and columns nondecreasing.
Terms
- a(0) =20a(1) =400a(2) =4884a(3) =41682a(4) =273959a(5) =1477240a(6) =6818350a(7) =27746619a(8) =101698292a(9) =341120712a(10) =1060013078a(11) =3081189588a(12) =8443340635a(13) =21952389700a(14) =54443494785a(15) =129382581759a(16) =295772387822a(17) =652604111790
External references
- oeis: A223866