Diagonal sums of number triangle A110180.

Terms

a(0) =1a(1) =1a(2) =2a(3) =2a(4) =5a(5) =9a(6) =26a(7) =66a(8) =199a(9) =575a(10) =1790a(11) =5542a(12) =17945a(13) =58733a(14) =198880a(15) =685296a(16) =2429281a(17) =8778321a(18) =32491940a(19) =122503412a(20) =471379771a(21) =1844669495a(22) =7346727298a(23) =29712688698a(24) =122054603983a(25) =508548201863