Partial sums of A014827.

Terms

a(0) =1a(1) =8a(2) =46a(3) =240a(4) =1215a(5) =6096a(6) =30508a(7) =152576a(8) =762925a(9) =3814680a(10) =19073466a(11) =95367408a(12) =476837131a(13) =2384185760a(14) =11920928920a(15) =59604644736a(16) =298023223833