cp's OEIS Frontend

A267928 Number of n X 1 0..3 arrays with every repeated value in every row and column greater than the previous repeated value.

%I A267928 #10 Feb 25 2018 09:15:37
%S A267928 4,16,60,222,804,2872,10132,35383,122480,420752,1435736,4870132,
%T A267928 16432216,55178416,184481816,614348813,2038435340,6740997616,
%U A267928 22223182372,73053304378,239502956924,783241953896,2555428926860,8319101465587
%N A267928 Number of n X 1 0..3 arrays with every repeated value in every row and column greater than the previous repeated value.
%C A267928 Column 1 of A267933.
%H A267928 R. H. Hardin, <a href="/A267928/b267928.txt">Table of n, a(n) for n = 1..210</a>
%F A267928 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 A267928 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 A267928 Some solutions for n=8
%e A267928 ..2....0....3....1....3....1....2....2....1....3....2....0....0....1....1....0
%e A267928 ..1....1....1....2....2....0....1....2....0....1....3....1....0....1....1....3
%e A267928 ..2....0....3....1....1....2....1....3....0....0....1....3....1....0....3....1
%e A267928 ..0....0....0....2....3....0....2....3....2....3....2....1....0....1....1....2
%e A267928 ..3....1....1....0....3....2....0....2....0....0....1....0....2....3....2....1
%e A267928 ..1....1....2....3....1....1....2....0....2....2....1....2....0....3....3....2
%e A267928 ..1....2....1....1....2....3....1....2....1....0....3....3....3....0....0....3
%e A267928 ..3....3....1....3....3....1....0....0....3....3....0....0....1....3....3....3
%Y A267928 Cf. A267933.
%K A267928 nonn
%O A267928 1,1
%A A267928 _R. H. Hardin_, Jan 22 2016