Triangle of trinomial coefficients T(n,k) (n >= 0, 0 <= k <= 2*n), read by rows: n-th row is obtained by expanding (1 + x + x^2)^n.
A027907
Triangle of trinomial coefficients T(n,k) (n >= 0, 0 <= k <= 2*n), read by rows: n-th row is obtained by expanding (1 + x + x^2)^n.
Terms
- a(0) =1a(1) =1a(2) =1a(3) =1a(4) =1a(5) =2a(6) =3a(7) =2a(8) =1a(9) =1a(10) =3a(11) =6a(12) =7a(13) =6a(14) =3a(15) =1a(16) =1a(17) =4a(18) =10a(19) =16a(20) =19a(21) =16a(22) =10a(23) =4a(24) =1a(25) =1a(26) =5a(27) =15a(28) =30a(29) =45
External references
- oeis: A027907