A183995 - OEIS

%I #8 Apr 09 2018 09:59:28

%S 81,171,361,855,2025,5175,13225,35535,95481,265431,737881,2100255,

%T 5978025,17298375,50055625,146516175,428862681,1265299191,3733087801,

%U 11073888255,32849750025,97806145575,291205933225,869194951215

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

%C Column 1 of A184003.

%H R. H. Hardin, <a href="/A183995/b183995.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*(81 - 315*x - 665*x^2 + 3549*x^3 + 270*x^4 - 12000*x^5 + 6300*x^6 + 12420*x^7 - 9720*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 2:

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

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

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

%Y Cf. A184003.

%K nonn

%O 1,1

%A _R. H. Hardin_, Jan 08 2011