Number of 3Xn 0..3 arrays with rows unimodal and columns nondecreasing.

A223988

Number of 3Xn 0..3 arrays with rows unimodal and columns nondecreasing.

Terms

    a(0) =20a(1) =400a(2) =5029a(3) =44803a(4) =308470a(5) =1738756a(6) =8350154a(7) =35158856a(8) =132595894a(9) =455284536a(10) =1441678804a(11) =4253578398a(12) =11791889562a(13) =30929283640a(14) =77204065141a(15) =184304047745a(16) =422556706314a(17) =933834642586

External references