a(n) is the rank of row n of A130517 in a lexicographic permutation of [1, ..., n].

A375303

a(n) is the rank of row n of A130517 in a lexicographic permutation of [1, ..., n].

Terms

    a(0) =0a(1) =1a(2) =4a(3) =20a(4) =108a(5) =678a(6) =4848a(7) =39264a(8) =355920a(9) =3575640a(10) =39454560a(11) =474501600a(12) =6178566240a(13) =86606881200

External references