Triangular array read by rows: T(n, k) = S(n, [n/2]-k) and S(n,k) = C(n, 2*k)*(2*k-1)!!*((2*k-1)!! + 1)/2, n>=0, 0<=k<=[n/2].

A246257

Triangular array read by rows: T(n, k) = S(n, [n/2]-k) and S(n,k) = C(n, 2*k)*(2*k-1)!!*((2*k-1)!! + 1)/2, n>=0, 0<=k<=[n/2].

Terms

    a(0) =1a(1) =1a(2) =1a(3) =1a(4) =3a(5) =1a(6) =6a(7) =6a(8) =1a(9) =30a(10) =10a(11) =1a(12) =120a(13) =90a(14) =15a(15) =1a(16) =840a(17) =210a(18) =21a(19) =1a(20) =5565a(21) =3360a(22) =420a(23) =28a(24) =1a(25) =50085a(26) =10080a(27) =756a(28) =36a(29) =1

External references