Triangle with subscripts (1,1),(2,1),(1,2),(3,1),(2,2),(1,3), etc. in which entry (i,j) is i AND j.

Terms

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