A242547 - OEIS

%I #4 May 17 2014 09:36:13

%S 13,43,166,712,3339,16968,92360,532175,3210136,20066475,128848615,

%T 843831762,5605476437,37615886287,254237240993,1726996739311,

%U 11772647808288,80450209850112,550717024856208,3774443585348691

%N Number of length n+3 0..6 arrays with no four elements in a row with pattern aabb (possibly a=b) and new values 0..6 introduced in 0..6 order

%C Column 6 of A242549

%H R. H. Hardin, <a href="/A242547/b242547.txt">Table of n, a(n) for n = 1..210</a>

%F Empirical: a(n) = 16*a(n-1) -95*a(n-2) +326*a(n-3) -998*a(n-4) +2268*a(n-5) -2953*a(n-6) +5002*a(n-7) -877*a(n-8) -8932*a(n-9) -5460*a(n-10) -46536*a(n-11) -36728*a(n-12) -4608*a(n-13) +43488*a(n-14) +180288*a(n-15) +260208*a(n-16) +254016*a(n-17) +207360*a(n-18) +103680*a(n-19) +20736*a(n-20)

%e Some solutions for n=4

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

%e ..1....0....1....1....1....1....1....1....0....1....1....1....1....1....0....1

%e ..1....0....2....0....2....1....2....1....1....2....2....2....1....2....1....0

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

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

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

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

%K nonn

%O 1,1

%A _R. H. Hardin_, May 17 2014