Number of letters in German name of n.

Terms

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