Define an array by d(m, 0) = 1, d(m, 1) = m; d(m, k) = (m - k + 1) d(m+1, k-1) - (k-1) (m+1) d(m+2, k-2). Sequence gives d(2,n).

A127067

Define an array by d(m, 0) = 1, d(m, 1) = m; d(m, k) = (m - k + 1) d(m+1, k-1) - (k-1) (m+1) d(m+2, k-2). Sequence gives d(2,n).

Terms

    a(0) =1a(1) =2a(2) =0a(3) =-24a(4) =-60a(5) =720a(6) =5040a(7) =-40320a(8) =-589680a(9) =3628800a(10) =99792000a(11) =-479001600a(12) =-23740516800a(13) =87178291200

External references