Number of letters in n (in Italian).

Terms

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