Number of 2's when k is written in base b for all b and k satisfying 2<=b<=n+1, 1<=k<=n.

Terms

a(0) =0a(1) =1a(2) =1a(3) =1a(4) =2a(5) =4a(6) =6a(7) =10a(8) =12a(9) =16a(10) =20a(11) =24a(12) =27a(13) =34a(14) =38a(15) =44a(16) =51a(17) =58a(18) =63a(19) =72a(20) =77a(21) =86a(22) =94a(23) =103a(24) =111a(25) =125a(26) =132a(27) =139a(28) =147a(29) =156