1/6 the number of (n+2)X6 0..2 arrays with each 3X3 subblock containing one of one value, four of another, and four of the last.
A184472
1/6 the number of (n+2)X6 0..2 arrays with each 3X3 subblock containing one of one value, four of another, and four of the last.
Terms
- a(0) =12339a(1) =19119a(2) =30681a(3) =53739a(4) =127689a(5) =322275a(6) =878625a(7) =2967411a(8) =9800745a(9) =32238603a(10) =121975089a(11) =436928547a(12) =1519783929a(13) =5949509979a(14) =21894837441a(15) =77688357939a(16) =307915900809
External references
- oeis: A184472