T(n, 2n-8), T given by A027926.

Terms

a(0) =1a(1) =2a(2) =5a(3) =13a(4) =34a(5) =88a(6) =221a(7) =530a(8) =1204a(9) =2587a(10) =5270a(11) =10220a(12) =18955a(13) =33775a(14) =58060a(15) =96647a(16) =156299a(17) =246280a(18) =379051a(19) =571103a(20) =843944a(21) =1225258a(22) =1750255a(23) =2463232a(24) =3419366a(25) =4686761a(26) =6348772a(27) =8506630a(28) =11282393a(29) =14822249