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%I #8 Nov 06 2018 08:19:55
%S 124,260,548,1156,2436,5132,10812,22780,47996,101124,213060,448900,
%T 945796,1992716,4198492,8845884,18637564,39267844,82734180,174314244,
%U 367266052,773799948,1630334076,3434982396,7237230844,15248261636
%N Number of length n+4 0..3 arrays with no pair in any consecutive five terms totalling exactly 3.
%H R. H. Hardin, <a href="/A246732/b246732.txt">Table of n, a(n) for n = 1..210</a>
%F Empirical: a(n) = 2*a(n-1) + a(n-4).
%F Empirical g.f.: 4*x*(31 + 3*x + 7*x^2 + 15*x^3) / (1 - 2*x - x^4). - _Colin Barker_, Nov 06 2018
%e Some solutions for n=4:
%e ..2....3....0....1....0....1....2....1....0....1....3....1....2....3....1....0
%e ..3....1....1....1....2....0....3....1....2....1....3....3....3....1....1....0
%e ..2....1....0....3....2....0....3....1....2....1....3....1....3....3....3....0
%e ..2....3....0....1....2....0....3....1....2....1....1....3....3....3....3....0
%e ..2....3....1....3....0....1....3....1....0....1....3....1....3....3....3....2
%e ..2....3....1....3....0....0....2....1....2....3....1....1....3....3....3....0
%e ..2....1....1....3....2....0....3....1....2....1....3....1....1....3....1....2
%e ..0....1....1....3....2....0....2....0....2....3....1....3....1....1....1....2
%Y Column 3 of A246737.
%K nonn
%O 1,1
%A _R. H. Hardin_, Sep 02 2014
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