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A246744 Number of length 7+4 0..n arrays with no pair in any consecutive five terms totalling exactly n.

%I A246744 #6 Jul 23 2025 11:32:31
%S A246744 2,68,10812,135776,2818830,19906740,162700376,766650656,3696053370,
%T A246744 13019727620,45166073172,128894476608,358710268742,876273071156,
%U A246744 2086036196400,4529314688960,9603337631346,19024638124356,36902088232940
%N A246744 Number of length 7+4 0..n arrays with no pair in any consecutive five terms totalling exactly n.
%C A246744 Row 7 of A246737
%H A246744 R. H. Hardin, <a href="/A246744/b246744.txt">Table of n, a(n) for n = 1..56</a>
%F A246744 Empirical: a(n) = 3*a(n-1) +6*a(n-2) -26*a(n-3) -9*a(n-4) +99*a(n-5) -24*a(n-6) -216*a(n-7) +126*a(n-8) +294*a(n-9) -252*a(n-10) -252*a(n-11) +294*a(n-12) +126*a(n-13) -216*a(n-14) -24*a(n-15) +99*a(n-16) -9*a(n-17) -26*a(n-18) +6*a(n-19) +3*a(n-20) -a(n-21)
%e A246744 Some solutions for n=4
%e A246744 ..2....2....0....1....1....0....2....3....0....0....3....2....1....1....2....0
%e A246744 ..1....0....2....2....4....1....3....2....1....2....0....3....1....0....0....0
%e A246744 ..1....0....1....1....4....2....0....4....0....1....0....3....1....1....0....0
%e A246744 ..0....1....1....1....1....0....3....3....1....1....0....4....1....0....0....0
%e A246744 ..1....1....1....4....4....1....0....3....0....1....0....3....1....2....0....0
%e A246744 ..2....0....0....4....1....1....3....3....1....1....0....3....1....0....1....0
%e A246744 ..0....2....1....4....1....1....3....2....0....1....0....4....0....0....1....0
%e A246744 ..1....1....1....1....2....1....3....3....0....0....1....3....1....1....1....0
%e A246744 ..1....1....2....4....1....0....3....4....0....1....1....4....1....0....1....3
%e A246744 ..0....0....0....1....1....2....4....3....0....0....2....4....0....0....2....3
%e A246744 ..2....0....1....2....0....1....3....3....3....2....1....2....1....2....1....0
%K A246744 nonn
%O A246744 1,1
%A A246744 _R. H. Hardin_, Sep 02 2014