Number of words w of length n such that each letter of the quinary 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.
A321841
Number of words w of length n such that each letter of the quinary 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) =120a(1) =360a(2) =1470a(3) =4872a(4) =17649a(5) =60465a(6) =218360a(7) =779649a(8) =2878543a(9) =10662640a(10) =40402105a(11) =154308568a(12) =599106195a(13) =2346709225a(14) =9308176915a(15) =37232621263a(16) =150428771629a(17) =612404221280
External references
- oeis: A321841