Number of defective 4-colorings of an n X 1 0..3 array connected horizontally, antidiagonally and vertically with exactly two mistakes, and colors introduced in row-major 0..3 order.
A229665
Number of defective 4-colorings of an n X 1 0..3 array connected horizontally, antidiagonally and vertically with exactly two mistakes, and colors introduced in row-major 0..3 order.
Terms
- a(0) =0a(1) =0a(2) =1a(3) =3a(4) =12a(5) =50a(6) =210a(7) =861a(8) =3416a(9) =13140a(10) =49230a(11) =180455a(12) =649572a(13) =2302950a(14) =8060234a(15) =27900705a(16) =95659440a(17) =325241960a(18) =1097691462a(19) =3680494731a(20) =12268315580a(21) =40679151450a(22) =134241199554a(23) =441078226853
External references
- oeis: A229665