Row sums of A208657.

Terms

a(0) =0a(1) =4a(2) =17a(3) =52a(4) =139a(5) =346a(6) =825a(7) =1912a(8) =4343a(9) =9718a(10) =21493a(11) =47092a(12) =102387a(13) =221170a(14) =475121a(15) =1015792a(16) =2162671a(17) =4587502a(18) =9699309a(19) =20447212a(20) =42991595a(21) =90177514a(22) =188743657a(23) =394264552a(24) =822083559a(25) =1711276006a(26) =3556769765a(27) =7381975012