Diagonal sums of generalized Narayana triangle A180957.

Terms

a(0) =1a(1) =1a(2) =2a(3) =2a(4) =2a(5) =-1a(6) =-8a(7) =-25a(8) =-57a(9) =-114a(10) =-202a(11) =-322a(12) =-447a(13) =-496a(14) =-271a(15) =625a(16) =2914a(17) =7762a(18) =16834a(19) =32063a(20) =54760a(21) =83319a(22) =108375a(23) =103726a(24) =11110a(25) =-282498a(26) =-973439a(27) =-2366432a(28) =-4869919a(29) =-8903455