Number of vowels in the American English name of n.

Terms

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