Number of binary [ n,4 ] codes.

Terms

a(0) =0a(1) =0a(2) =0a(3) =1a(4) =5a(5) =16a(6) =43a(7) =106a(8) =240a(9) =516a(10) =1060a(11) =2108a(12) =4064a(13) =7641a(14) =14036a(15) =25253a(16) =44560a(17) =77245a(18) =131658a(19) =220883a(20) =365027a(21) =594674a(22) =955649a(23) =1515908a(24) =2374875a(25) =3676632a(26) =5627587a(27) =8520689a(28) =12767557a(29) =18941641