a(n) = A109890(A111315(n)).

Terms

a(0) =3a(1) =6a(2) =113573a(3) =230801a(4) =941071a(5) =5166859a(6) =30956561a(7) =123081011a(8) =3050325741a(9) =14086296281a(10) =60060345973a(11) =120331687901a(12) =316465918571a(13) =634257678809