a(n) = (1/3)*A054640(n) for n >= 1.

A374852

a(n) = (1/3)*A054640(n) for n >= 1.

Terms

    a(0) =1a(1) =4a(2) =24a(3) =192a(4) =2304a(5) =32256a(6) =580608a(7) =11612160a(8) =278691840a(9) =8360755200a(10) =267544166400

External references