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

Terms

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