cp's OEIS Frontend

A321041 Number of words of length 6n such that all letters of the n-ary alphabet occur at least once and are introduced in ascending order and which can be built by repeatedly inserting triples of identical letters into the initially empty word.

%I A321041 #5 Oct 26 2018 15:45:12
%S A321041 1,1,97,29886,16482191,13337746758,14329297278912,19256258184412314,
%T A321041 31120996552066805175,58830559749207291469515,
%U A321041 127426007577261157375345878,311250333529456439224989700168,846594239519776323268829614117536,2538054216720547203941994076323844425
%N A321041 Number of words of length 6n such that all letters of the n-ary alphabet occur at least once and are introduced in ascending order and which can be built by repeatedly inserting triples of identical letters into the initially empty word.
%H A321041 Alois P. Heinz, <a href="/A321041/b321041.txt">Table of n, a(n) for n = 0..230</a>
%F A321041 a(n) = A256311(2n,n).
%Y A321041 Cf. A256311.
%K A321041 nonn
%O A321041 0,3
%A A321041 _Alois P. Heinz_, Oct 26 2018