Number of 3'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) =0a(2) =1a(3) =1a(4) =1a(5) =1a(6) =2a(7) =3a(8) =4a(9) =5a(10) =7a(11) =9a(12) =12a(13) =14a(14) =19a(15) =21a(16) =24a(17) =28a(18) =33a(19) =35a(20) =40a(21) =43a(22) =49a(23) =53a(24) =57a(25) =60a(26) =68a(27) =73a(28) =78a(29) =84