Number of chisel strokes required for Roman numerals for n.

Terms

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