Number of defective 4-colorings of an n X 1 0..3 array connected horizontally, antidiagonally and vertically with exactly one mistake, and colors introduced in row-major 0..3 order.
A229472
Number of defective 4-colorings of an n X 1 0..3 array connected horizontally, antidiagonally and vertically with exactly one mistake, and colors introduced in row-major 0..3 order.
Terms
- a(0) =0a(1) =1a(2) =2a(3) =6a(4) =20a(5) =70a(6) =246a(7) =854a(8) =2920a(9) =9846a(10) =32810a(11) =108262a(12) =354300a(13) =1151462a(14) =3720094a(15) =11957430a(16) =38263760a(17) =121965718a(18) =387420498a(19) =1226831558a(20) =3874204900a(21) =12203745414a(22) =38354628422a(23) =120294061846a(24) =376572715320
External references
- oeis: A229472