Number of n X 4 0..2 arrays with horizontal differences mod 3 never 1, vertical differences mod 3 never -1, rows lexicographically nondecreasing, and columns lexicographically nonincreasing.
A229424
Number of n X 4 0..2 arrays with horizontal differences mod 3 never 1, vertical differences mod 3 never -1, rows lexicographically nondecreasing, and columns lexicographically nonincreasing.
Terms
- a(0) =12a(1) =55a(2) =222a(3) =754a(4) =2204a(5) =5700a(6) =13345a(7) =28794a(8) =58053a(9) =110550a(10) =200533a(11) =348855a(12) =585211a(13) =950897a(14) =1502166a(15) =2314261a(16) =3486210a(17) =5146473a(18) =7459536a(19) =10633552a(20) =14929134a(21) =20669410a(22) =28251455a(23) =38159220a(24) =50978083a(25) =67411152a(26) =88297455a(27) =114632157
External references
- oeis: A229424