Number of n X 3 0..3 arrays with rows and columns lexicographically nondecreasing read forwards and nonincreasing read backwards.

A201976

Number of n X 3 0..3 arrays with rows and columns lexicographically nondecreasing read forwards and nonincreasing read backwards.

Terms

    a(0) =4a(1) =72a(2) =1372a(3) =9260a(4) =38112a(5) =117744a(6) =301612a(7) =676792a(8) =1375740a(9) =2589832a(10) =4584684a(11) =7717252a(12) =12454712a(13) =19395120a(14) =29289852a(15) =43067824a(16) =61861492a(17) =87034632a(18) =120211900a(19) =163310172a(20) =218571664a(21) =288598832a(22) =376391052a(23) =485383080a(24) =619485292a(25) =783125704

External references