Irregular triangle read by rows: T(n,k) is the number of binary pattern classes in the (3,n)-rectangular grid with k '1's and (3n-k) '0's: two patterns are in same class if one of them can be obtained by a reflection or 180-degree rotation of the other.
A226290
Irregular triangle read by rows: T(n,k) is the number of binary pattern classes in the (3,n)-rectangular grid with k '1's and (3n-k) '0's: two patterns are in same class if one of them can be obtained by a reflection or 180-degree rotation of the other.
Terms
- a(0) =1a(1) =1a(2) =2a(3) =2a(4) =1a(5) =1a(6) =2a(7) =6a(8) =6a(9) =6a(10) =2a(11) =1a(12) =1a(13) =4a(14) =13a(15) =27a(16) =39a(17) =39a(18) =27a(19) =13a(20) =4a(21) =1a(22) =1a(23) =4a(24) =22a(25) =60a(26) =139a(27) =208a(28) =252a(29) =208
External references
- oeis: A226290