Triangle T(n,k), 0 <= k <= n, read by rows, defined by T(0,0) = 1; T(0,k) = 0 if k < 0 or if k > 0; T(n,k) = k*T(n-1,k-1) + (k+2)*T(n-1,k+1).

A107729

Triangle T(n,k), 0 <= k <= n, read by rows, defined by T(0,0) = 1; T(0,k) = 0 if k < 0 or if k > 0; T(n,k) = k*T(n-1,k-1) + (k+2)*T(n-1,k+1).

Terms

    a(0) =1a(1) =0a(2) =1a(3) =2a(4) =0a(5) =2a(6) =0a(7) =8a(8) =0a(9) =6a(10) =16a(11) =0a(12) =40a(13) =0a(14) =24a(15) =0a(16) =136a(17) =0a(18) =240a(19) =0a(20) =120a(21) =272a(22) =0a(23) =1232a(24) =0a(25) =1680a(26) =0a(27) =720a(28) =0a(29) =3968

External references