Number of n-length words w over 4-ary alphabet such that 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.
A213292
Number of n-length words w over 4-ary alphabet such that 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) =1a(1) =4a(2) =16a(3) =46a(4) =118a(5) =276a(6) =712a(7) =1805a(8) =4895a(9) =13280a(10) =37993a(11) =109386a(12) =328219a(13) =992413a(14) =3101399a(15) =9764376a(16) =31580645a(17) =102797899a(18) =342075208a(19) =1144125506a(20) =3896297053a(21) =13319243655a(22) =46206520968a(23) =160729837020a(24) =565901313043
External references
- oeis: A213292