Number of ternary codes of length 3 with n words.

Terms

a(0) =1a(1) =1a(2) =3a(3) =10a(4) =34a(5) =105a(6) =321a(7) =846a(8) =1984a(9) =4023a(10) =7074a(11) =10770a(12) =14253a(13) =16384a(14) =16384a(15) =14253a(16) =10770a(17) =7074a(18) =4023a(19) =1984a(20) =846a(21) =321a(22) =105a(23) =34a(24) =10a(25) =3a(26) =1a(27) =1