Number of binary codes (not necessarily linear) of length n with 3 words.

Terms

a(0) =0a(1) =1a(2) =3a(3) =6a(4) =10a(5) =16a(6) =23a(7) =32a(8) =43a(9) =56a(10) =71a(11) =89a(12) =109a(13) =132a(14) =158a(15) =187a(16) =219a(17) =255a(18) =294a(19) =337a(20) =384a(21) =435a(22) =490a(23) =550a(24) =614a(25) =683a(26) =757a(27) =836a(28) =920a(29) =1010