Number of letters in n (in Dutch) counting 'ij' as one letter.

Terms

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