a(n) = (Sum_{k=0..n-1} A246065(k)) / n^2.

Terms

a(0) =-1a(1) =0a(2) =1a(3) =3a(4) =9a(5) =32a(6) =135a(7) =648a(8) =3409a(9) =19176a(10) =113535a(11) =700125a(12) =4463415a(13) =29256120a(14) =196334697a(15) =1344542787a(16) =9371335905a(17) =66335058128a(18) =476022873279