Triangle T(n,k) (n >= 0, 0 <= k <= n) read by rows: T(n,0) = T(n,1) = A000984(n); for n >= 2 and k >= 2, T(n,k) = T(n,k-1) - T(n-1,k-2).

A171661

Triangle T(n,k) (n >= 0, 0 <= k <= n) read by rows: T(n,0) = T(n,1) = A000984(n); for n >= 2 and k >= 2, T(n,k) = T(n,k-1) - T(n-1,k-2).

Terms

    a(0) =1a(1) =2a(2) =2a(3) =6a(4) =6a(5) =4a(6) =20a(7) =20a(8) =14a(9) =8a(10) =70a(11) =70a(12) =50a(13) =30a(14) =16a(15) =252a(16) =252a(17) =182a(18) =112a(19) =62a(20) =32a(21) =924a(22) =924a(23) =672a(24) =420a(25) =238a(26) =126a(27) =64a(28) =3432a(29) =3432

External references