The total number of nonempty words in all length n finite languages on an alphabet of two letters.

A216158

The total number of nonempty words in all length n finite languages on an alphabet of two letters.

Terms

    a(0) =0a(1) =2a(2) =6a(3) =24a(4) =72a(5) =220a(6) =652a(7) =1848a(8) =5160a(9) =14130a(10) =38102a(11) =101296a(12) =266328a(13) =692740a(14) =1785524a(15) =4563888a(16) =11577888a(17) =29170128a(18) =73032808a(19) =181793136a(20) =450100760a(21) =1108868820a(22) =2719167020a(23) =6639085968a(24) =16144137800a(25) =39107596850a(26) =94393612782a(27) =227062741160a(28) =544439640328

External references