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Number of length 6+2 0..n arrays with no pair in any consecutive three terms totalling exactly n.
1

%I #6 Dec 28 2023 19:31:54

%S 2,56,2308,23168,171942,795144,3057032,9401216,25819210,62402840,

%T 139927692,288998016,566057198,1047126248,1862251792,3175741184,

%U 5253738642,8416795896,13163097620,20070807680,30009814582,43960191176

%N Number of length 6+2 0..n arrays with no pair in any consecutive three terms totalling exactly n.

%C Row 6 of A245995.

%H R. H. Hardin, <a href="/A246001/b246001.txt">Table of n, a(n) for n = 1..210</a>

%F Empirical: a(n) = 3*a(n-1) +3*a(n-2) -17*a(n-3) +3*a(n-4) +39*a(n-5) -25*a(n-6) -45*a(n-7) +45*a(n-8) +25*a(n-9) -39*a(n-10) -3*a(n-11) +17*a(n-12) -3*a(n-13) -3*a(n-14) +a(n-15).

%e Some solutions for n=5

%e ..0....4....3....3....0....1....0....0....4....1....4....3....0....0....4....1

%e ..3....4....3....0....4....0....4....1....3....1....4....3....3....3....0....1

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

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

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

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

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

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

%Y Cf. A245995.

%K nonn

%O 1,1

%A _R. H. Hardin_, Aug 09 2014