A321839 - OEIS

%I #10 Nov 21 2018 11:43:16

%S 6,12,35,87,232,599,1591,4202,11262,30221,81834,222321,607871,1668296,

%T 4601369,12737394,35401272,98716505,276192166,774988564,2180739865,

%U 6151939960,17396648770,49303165809,140018238988,398407130710,1135670120668,3242697225865

%N Number of words w of length n such that each letter of the ternary 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.

%H Alois P. Heinz, <a href="/A321839/b321839.txt">Table of n, a(n) for n = 3..2102</a>

%H Vaclav Kotesovec, <a href="/A321839/a321839.txt">Recurrence (of order 7)</a>

%F a(n) ~ 797 * 3^(n - 3/2) / (32 * sqrt(Pi) * n^(3/2)). - _Vaclav Kotesovec_, Nov 21 2018

%Y Column k=3 of A257783.

%K nonn

%O 3,1

%A _Alois P. Heinz_, Nov 19 2018