Triangular array, read by rows: second differences in n,n direction of trinomial array A027907.

Terms

a(0) =1a(1) =1a(2) =0a(3) =1a(4) =1a(5) =0a(6) =2a(7) =0a(8) =1a(9) =1a(10) =1a(11) =3a(12) =2a(13) =3a(14) =1a(15) =1a(16) =1a(17) =2a(18) =5a(19) =6a(20) =8a(21) =6a(22) =5a(23) =2a(24) =1a(25) =1a(26) =3a(27) =8a(28) =13a(29) =19