A hierarchical sequence (S(W'2{3}c) - see A059126).

A059155

A hierarchical sequence (S(W'2{3}c) - see A059126).

Terms

    a(0) =12a(1) =120a(2) =1008a(3) =8160a(4) =65472a(5) =524160a(6) =4194048a(7) =33553920a(8) =268434432a(9) =2147481600a(10) =17179865088a(11) =137438945280

External references