Number of n X 2 0..2 arrays with horizontal differences mod 3 never 1, vertical differences mod 3 never -1, and rows and columns lexicographically nondecreasing.

A229439

Number of n X 2 0..2 arrays with horizontal differences mod 3 never 1, vertical differences mod 3 never -1, and rows and columns lexicographically nondecreasing.

Terms

    a(0) =4a(1) =7a(2) =13a(3) =25a(4) =47a(5) =84a(6) =142a(7) =228a(8) =350a(9) =517a(10) =739a(11) =1027a(12) =1393a(13) =1850a(14) =2412a(15) =3094a(16) =3912a(17) =4883a(18) =6025a(19) =7357a(20) =8899a(21) =10672a(22) =12698a(23) =15000a(24) =17602a(25) =20529a(26) =23807a(27) =27463a(28) =31525a(29) =36022

External references