Triangle T(n,k)= binomial(n + k,n) + binomial(2*n-k,n) read by rows.

Terms

a(0) =2a(1) =3a(2) =3a(3) =7a(4) =6a(5) =7a(6) =21a(7) =14a(8) =14a(9) =21a(10) =71a(11) =40a(12) =30a(13) =40a(14) =71a(15) =253a(16) =132a(17) =77a(18) =77a(19) =132a(20) =253a(21) =925a(22) =469a(23) =238a(24) =168a(25) =238a(26) =469a(27) =925a(28) =3433a(29) =1724