Number of words w of length n such that each letter of the binary alphabet is used at least once and for every prefix z of w we have #(z,a_i) = 0 or #(z,a_i) >= #(z,a_j) for all j>i and #(z,a_i) counts the occurrences of the i-th letter in z.
A321838
Number of words w of length n such that each letter of the binary alphabet is used at least once and for every prefix z of w we have #(z,a_i) = 0 or #(z,a_i) >= #(z,a_j) for all j>i and #(z,a_i) counts the occurrences of the i-th letter in z.
Terms
- a(0) =2a(1) =3a(2) =7a(3) =12a(4) =25a(5) =44a(6) =89a(7) =160a(8) =321a(9) =587a(10) =1175a(11) =2177a(12) =4355a(13) =8150a(14) =16301a(15) =30744a(16) =61489a(17) =116687a(18) =233375a(19) =445093a(20) =890187a(21) =1704793a(22) =3409587a(23) =6552377a(24) =13104755a(25) =25258599a(26) =50517199a(27) =97617059a(28) =195234119a(29) =378098954
External references
- oeis: A321838