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%I #6 May 12 2016 04:52:26
%S 115,589,3089,16911,91777,502971,2746607,15040763,82261821,450304289,
%T 2463907651,13485492509,73797670811,403887709287,2210318878259,
%U 12096617815013,66200984952569,362301557191539,1982772302106141
%N Number of (n+1)X(4+1) 0..1 arrays with no 2X2 subblock having zero or two 1s
%C Column 4 of A251219
%H R. H. Hardin, <a href="/A251215/b251215.txt">Table of n, a(n) for n = 1..210</a>
%F Empirical: a(n) = 6*a(n-1) +22*a(n-2) -157*a(n-3) -115*a(n-4) +1491*a(n-5) -328*a(n-6) -6480*a(n-7) +4148*a(n-8) +13794*a(n-9) -11784*a(n-10) -13976*a(n-11) +13612*a(n-12) +6008*a(n-13) -6440*a(n-14) -768*a(n-15) +960*a(n-16).
%F Empirical: G.f.: -x*(115 -101*x -2975*x^2 +3474*x^3 +28051*x^4 -38490*x^5 -120530*x^6 +182206*x^7 +251282*x^8 -409920*x^9 -244852*x^10 +435820*x^11 +97696*x^12 -200768*x^13 -9984*x^14 +30208*x^15) / ( -1 +6*x +22*x^2 -157*x^3 -115*x^4 +1491*x^5 -328*x^6 -6480*x^7 +4148*x^8 +13794*x^9 -11784*x^10 -13976*x^11 +13612*x^12 +6008*x^13 -6440*x^14 -768*x^15 +960*x^16 ). - _R. J. Mathar_, May 12 2016
%e Some solutions for n=4
%e ..1..1..1..1..1....1..1..0..1..1....0..0..1..0..1....0..1..1..1..0
%e ..1..1..0..1..1....1..1..1..1..1....0..1..1..1..1....1..1..1..1..1
%e ..1..1..1..1..1....0..1..0..1..1....1..1..1..0..1....0..1..1..1..0
%e ..0..1..0..1..1....1..1..1..1..1....1..1..1..1..1....1..1..1..1..1
%e ..1..1..1..1..1....0..1..0..1..1....0..1..1..1..1....0..1..0..1..1
%K nonn
%O 1,1
%A _R. H. Hardin_, Nov 30 2014
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