a(n)=(# 1's)-(# 2's) in first n terms of A031219.

Terms

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