a(n) = A006551(n) - A018224(n).

Terms

a(0) =0a(1) =0a(2) =0a(3) =2a(4) =30a(5) =202a(6) =2016a(7) =14394a(8) =151290a(9) =1294478a(10) =15660744a(11) =162298842a(12) =2274318228a(13) =27968231436a(14) =447527038848