A183881 - OEIS

%I #5 Mar 31 2012 12:35:55

%S 1,1,1231,32521,424537,4079713,33702403,257404033,1885866973,

%T 13515603289,95750388631,674299155193,4734193668289,33187816266097,

%U 232479450595819,1627911123290065,11397233380815013,79786797746740777,558527947985495935

%N Number of arrangements of n+2 numbers in 0..6 with each number being the sum mod 7 of two others

%C Column 6 of A183884

%H R. H. Hardin, <a href="/A183881/b183881.txt">Table of n, a(n) for n = 1..80</a>

%e Some solutions for n=3

%e ..1....2....3....1....5....4....4....3....1....2....2....5....6....2....1....1

%e ..3....0....2....3....2....5....6....5....5....5....6....3....1....1....3....4

%e ..5....0....1....6....5....3....3....1....2....4....1....6....5....6....6....5

%e ..2....0....3....2....0....2....5....5....3....3....5....2....2....4....3....2

%e ..4....2....6....4....2....1....1....4....4....1....3....1....4....5....2....6

%K nonn

%O 1,3

%A _R. H. Hardin_ Jan 07 2011