%I #5 Mar 31 2012 12:37:01

%S 1,8,64,652,7120,82440,991152,12262470,155072356,1995610260,

%T 26048900628,344054761656,4589736845308,61750810543324,

%U 836935922008844,11416462124627925,156613134014878257,2159264087976308543

%N Number of length n+1 nonnegative integer arrays starting and ending with 0 with adjacent elements differing by no more than 7

%C Column 7 of A204213

%H R. H. Hardin, <a href="/A204212/b204212.txt">Table of n, a(n) for n = 1..210</a>

%e Some solutions for n=5

%e ..0....0....0....0....0....0....0....0....0....0....0....0....0....0....0....0

%e ..4....2....7....4....7....6....4....6....4....4....2....4....6....3....1....4

%e ..6....0....9....7....9....6....0....4....3....4....6....5....6....9....6...10

%e ..6....2...14....7...12....8....7....2....4....8....2....8....4....5....2...12

%e ..5....7....7....7....6....1....2....7....4....6....4....5....4....2....5....5

%e ..0....0....0....0....0....0....0....0....0....0....0....0....0....0....0....0

%K nonn

%O 1,2

%A _R. H. Hardin_ Jan 12 2012