Partial sums of A027035.

Terms

a(0) =1a(1) =3a(2) =8a(3) =22a(4) =61a(5) =173a(6) =496a(7) =1428a(8) =4121a(9) =11911a(10) =34476a(11) =99942a(12) =290185a(13) =843933a(14) =2458296a(15) =7171728a(16) =20952569a(17) =61295779a(18) =179539052a(19) =526476666a(20) =1545434817a(21) =4540842657a(22) =13353733048a(23) =39302395732a(24) =115759913681a(25) =341189589287