Number of n X 4 0..2 arrays with rows and columns lexicographically nondecreasing read forwards and nonincreasing read backwards.

A201696

Number of n X 4 0..2 arrays with rows and columns lexicographically nondecreasing read forwards and nonincreasing read backwards.

Terms

    a(0) =3a(1) =27a(2) =395a(3) =4998a(4) =35390a(5) =167625a(6) =607919a(7) =1826778a(8) =4775228a(9) =11211034a(10) =24167306a(11) =48600665a(12) =92261185a(13) =166831642a(14) =289389192a(15) =484248471a(16) =785251265a(17) =1238574341a(18) =1906133765a(19) =2869671064a(20) =4235613920a(21) =6140811719a(22) =8759254221a(23) =12309889872

External references