Number of 2's when n is written in base b for 2<=b<=n+1.

Terms

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