A183997 - OEIS

%I #8 Apr 09 2018 13:00:53

%S 361,579,977,1887,3793,8415,19217,47031,117601,308799,822977,2268807,

%T 6311953,17963055,51378737,149156151,434130241,1275821919,3754108577,

%U 11115905127,32933734513,97974065295,291541674257,869866334871

%N Number of (n+1) X 4 0..2 arrays with all 2 X 2 subblock sums the same.

%C Column 3 of A184003.

%H R. H. Hardin, <a href="/A183997/b183997.txt">Table of n, a(n) for n = 1..200</a>

%F Empirical: a(n) = 6*a(n-1) - 60*a(n-3) + 85*a(n-4) + 150*a(n-5) - 360*a(n-6) + 396*a(n-8) - 216*a(n-9).

%F Empirical g.f.: x*(361 - 1587*x - 2497*x^2 + 17685*x^3 - 3474*x^4 - 59088*x^5 + 42012*x^6 + 60804*x^7 - 56376*x^8) / ((1 - x)*(1 - 2*x)*(1 - 3*x)*(1 - 2*x^2)*(1 - 3*x^2)*(1 - 6*x^2)). - _Colin Barker_, Apr 09 2018

%e Some solutions for 3 X 4:

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

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

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

%Y Cf. A184003.

%K nonn

%O 1,1

%A _R. H. Hardin_, Jan 08 2011