Number of 2 X n 0..2 arrays with no element x(i,j) adjacent to value 2-x(i,j) horizontally, diagonally or antidiagonally.
A232921
Number of 2 X n 0..2 arrays with no element x(i,j) adjacent to value 2-x(i,j) horizontally, diagonally or antidiagonally.
Terms
- a(0) =9a(1) =18a(2) =54a(3) =144a(4) =396a(5) =1080a(6) =2952a(7) =8064a(8) =22032a(9) =60192a(10) =164448a(11) =449280a(12) =1227456a(13) =3353472a(14) =9161856a(15) =25030656a(16) =68385024a(17) =186831360a(18) =510432768a(19) =1394528256a(20) =3809922048a(21) =10408900608a(22) =28437645312a(23) =77693091840a(24) =212261474304
External references
- oeis: A232921