Number of n X 4 0..2 arrays with horizontal differences mod 3 never 1, vertical differences mod 3 never -1, and rows and columns lexicographically nondecreasing.
A229441
Number of n X 4 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) =6a(1) =14a(2) =37a(3) =109a(4) =324a(5) =915a(6) =2402a(7) =5843a(8) =13229a(9) =28071a(10) =56234a(11) =107080a(12) =194989a(13) =341334a(14) =576993a(15) =945488a(16) =1506848a(17) =2342300a(18) =3559899a(19) =5301215a(20) =7749202a(21) =11137381a(22) =15760476a(23) =21986649a(24) =30271487a(25) =41173901a(26) =55374104a(27) =73693842a(28) =97119059a(29) =126825184
External references
- oeis: A229441