cp's OEIS Frontend

A251146 Number of (n+1) X (5+1) 0..2 arrays with every 2 X 2 subblock summing to 4 and no 2 X 2 subblock having exactly two nonzero entries.

%I A251146 #17 Nov 26 2018 16:27:47
%S A251146 213,299,433,667,1061,1743,2925,5003,8689,15307,27317,49359,90237,
%T A251146 166811,311569,587515,1117445,2141775,4132941,8022251,15650353,
%U A251146 30663019,60294293,118919247,235137501,465904763,924738385,1838035483,3657558629
%N A251146 Number of (n+1) X (5+1) 0..2 arrays with every 2 X 2 subblock summing to 4 and no 2 X 2 subblock having exactly two nonzero entries.
%H A251146 R. H. Hardin, <a href="/A251146/b251146.txt">Table of n, a(n) for n = 1..210</a>
%F A251146 Empirical: a(n) = 3*a(n-1) - 5*a(n-3) + a(n-4) + 2*a(n-5).
%F A251146 Empirical g.f.: x*(213 - 340*x - 464*x^2 + 433*x^3 + 342*x^4) / ((1 - x)*(1 + x)*(1 - 2*x)*(1 - x - x^2)). - _Colin Barker_, Nov 26 2018
%e A251146 Some solutions for n=4:
%e A251146 ..1..1..1..2..0..1....1..2..1..2..0..1....2..1..2..1..1..1....1..0..1..0..2..1
%e A251146 ..0..2..0..1..1..2....0..1..0..1..1..2....0..1..0..1..1..1....2..1..2..1..1..0
%e A251146 ..1..1..1..2..0..1....2..1..2..1..1..0....1..2..1..2..0..2....1..0..1..0..2..1
%e A251146 ..0..2..0..1..1..2....0..1..0..1..1..2....0..1..0..1..1..1....2..1..2..1..1..0
%e A251146 ..1..1..1..2..0..1....2..1..2..1..1..0....1..2..1..2..0..2....0..1..0..1..1..2
%Y A251146 Column 5 of A251149.
%K A251146 nonn
%O A251146 1,1
%A A251146 _R. H. Hardin_, Nov 30 2014