Obverse convolution (1)**A000201; see Comments.

A374860

Obverse convolution (1)**A000201; see Comments.

Terms

    a(0) =1a(1) =2a(2) =8a(3) =40a(4) =280a(5) =2520a(6) =25200a(7) =302400a(8) =3931200a(9) =58968000a(10) =1002456000a(11) =18044208000a(12) =360884160000

External references