a(n) = a(n-1)*a(n-2)*a(n-3)*a(n-4); a(0..3) = (1, 1, 2, 3).

A299399

a(n) = a(n-1)*a(n-2)*a(n-3)*a(n-4); a(0..3) = (1, 1, 2, 3).

Terms

    a(0) =1a(1) =1a(2) =2a(3) =3a(4) =6a(5) =36a(6) =1296a(7) =839808a(8) =235092492288

External references