a(n) = Sum_{i=0..n} T(i,n-i), array T as in A049704.

Terms

a(0) =0a(1) =2a(2) =3a(3) =4a(4) =6a(5) =8a(6) =14a(7) =18a(8) =28a(9) =36a(10) =52a(11) =66a(12) =90a(13) =104a(14) =140a(15) =170a(16) =204a(17) =240a(18) =296a(19) =336a(20) =404a(21) =458a(22) =530a(23) =602a(24) =698a(25) =772a(26) =888a(27) =994a(28) =1108a(29) =1216