Triangle T(n,m) = Sum_{k=0..m} (-1)^(m-k)*binomial(m,k)*binomial(n-m+k-1,m-1)*binomial(2*n-3*m+k-1,n-m), T(n,n)=1.

A271776

Triangle T(n,m) = Sum_{k=0..m} (-1)^(m-k)*binomial(m,k)*binomial(n-m+k-1,m-1)*binomial(2*n-3*m+k-1,n-m), T(n,n)=1.

Terms

    a(0) =1a(1) =1a(2) =1a(3) =2a(4) =2a(5) =1a(6) =6a(7) =5a(8) =3a(9) =1a(10) =20a(11) =18a(12) =9a(13) =4a(14) =1a(15) =70a(16) =70a(17) =37a(18) =14a(19) =5a(20) =1a(21) =252a(22) =280a(23) =162a(24) =64a(25) =20a(26) =6a(27) =1a(28) =924a(29) =1134

External references