Number of n X 2 0..2 arrays with values 0..2 introduced in row major order, the number of instances of each value within one of each other, and no element equal to any horizontal or vertical neighbor.
A199127
Number of n X 2 0..2 arrays with values 0..2 introduced in row major order, the number of instances of each value within one of each other, and no element equal to any horizontal or vertical neighbor.
Terms
- a(0) =1a(1) =2a(2) =2a(3) =12a(4) =30a(5) =30a(6) =210a(7) =560a(8) =560a(9) =4200a(10) =11550a(11) =11550a(12) =90090a(13) =252252a(14) =252252a(15) =2018016a(16) =5717712a(17) =5717712a(18) =46558512a(19) =133024320a(20) =133024320a(21) =1097450640a(22) =3155170590a(23) =3155170590a(24) =26293088250a(25) =75957810500a(26) =75957810500a(27) =638045608200
External references
- oeis: A199127