cp's OEIS Frontend

A209185 Number of words, either empty or beginning with the first letter of the cyclic 6-ary alphabet, where each letter of the alphabet occurs n times and letters of neighboring word positions are equal or neighbors in the alphabet.

%I A209185 #5 Mar 30 2012 17:37:37
%S A209185 1,2,202,53768,19341130,8151741752,3795394507240,1892725627422240,
%T A209185 992594962274742090,540969426319412656280,303934170379321788972952,
%U A209185 175019302819674622982714912,102858166922334018149414066152,61493440878115135100772134725088
%N A209185 Number of words, either empty or beginning with the first letter of the cyclic 6-ary alphabet, where each letter of the alphabet occurs n times and letters of neighboring word positions are equal or neighbors in the alphabet.
%C A209185 The first and the last letters are considered neighbors in a cyclic alphabet.  The words are not considered cyclic here.
%C A209185 a(n) is also the number of (6*n-1)-step walks on 6-dimensional cubic lattice from (1,0,...,0) to (n,n,...,n) with positive unit steps in all dimensions such that the indices of dimensions used in consecutive steps differ by less than 2 or are in the set {1,6}.
%Y A209185 Column k=6 of A208879.
%K A209185 nonn,walk
%O A209185 0,2
%A A209185 _Alois P. Heinz_, Mar 05 2012