A267928 - OEIS

%I #10 Feb 25 2018 09:15:37

%S 4,16,60,222,804,2872,10132,35383,122480,420752,1435736,4870132,

%T 16432216,55178416,184481816,614348813,2038435340,6740997616,

%U 22223182372,73053304378,239502956924,783241953896,2555428926860,8319101465587

%N Number of n X 1 0..3 arrays with every repeated value in every row and column greater than the previous repeated value.

%C Column 1 of A267933.

%H R. H. Hardin, <a href="/A267928/b267928.txt">Table of n, a(n) for n = 1..210</a>

%F Empirical: a(n) = 12*a(n-1) - 48*a(n-2) + 44*a(n-3) + 150*a(n-4) - 252*a(n-5) - 216*a(n-6) + 324*a(n-7) + 243*a(n-8).

%F Empirical g.f.: x*(4 - 32*x + 60*x^2 + 94*x^3 - 284*x^4 - 152*x^5 + 388*x^6 + 259*x^7) / ((1 + x)^3*(1 - 3*x)^5). - _Colin Barker_, Feb 25 2018

%e Some solutions for n=8

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

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

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

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

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

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

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

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

%Y Cf. A267933.

%K nonn

%O 1,1

%A _R. H. Hardin_, Jan 22 2016