A183637 - OEIS

%I #10 Mar 31 2018 14:39:27

%S 1576,2884,6136,14644,38056,105604,309016,945364,3004936,9877924,

%T 33458296,116413684,414874216,1510107844,5598165976,21077667604,

%U 80389277896,309840123364,1204303904056,4712234595124,18534372807976

%N Number of (n+1) X 5 0..3 arrays with every 2 X 2 subblock summing to 6.

%C Column 4 of A183642.

%H R. H. Hardin, <a href="/A183637/b183637.txt">Table of n, a(n) for n = 1..200</a>

%F Empirical: a(n) = 10*a(n-1) - 35*a(n-2) + 50*a(n-3) - 24*a(n-4).

%F Conjectures from _Colin Barker_, Mar 31 2018: (Start)

%F G.f.: 4*x*(394 - 3219*x + 8114*x^2 - 6144*x^3) / ((1 - x)*(1 - 2*x)*(1 - 3*x)*(1 - 4*x)).

%F a(n) = 570 + 45*2^(3+n) + 10*3^(2+n) + 4^(1+n).

%F (End)

%e Some solutions for 3 X 5:

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

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

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

%Y Cf. A183642.

%K nonn

%O 1,1

%A _R. H. Hardin_, Jan 06 2011