A235305 - OEIS

%I #7 Jun 18 2022 23:19:50

%S 518,1106,2118,5042,10790,27602,64326,172658,428198,1187666,3077958,

%T 8734322,23346470,67327442,183958086,536636018,1489810598,4381851986,

%U 12310550598,36420793202,103261907750,306776867282,876096133446

%N Number of (n+1) X (3+1) 0..5 arrays with every 2 X 2 subblock having its diagonal sum differing from its antidiagonal sum by 6 (constant-stress 1 X 1 tilings).

%C Column 3 of A235310.

%H R. H. Hardin, <a href="/A235305/b235305.txt">Table of n, a(n) for n = 1..210</a>

%F Empirical: a(n) = 4*a(n-1) +25*a(n-2) -112*a(n-3) -231*a(n-4) +1260*a(n-5) +875*a(n-6) -7280*a(n-7) -224*a(n-8) +22736*a(n-9) -7980*a(n-10) -36288*a(n-11) +21456*a(n-12) +23040*a(n-13) -17280*a(n-14).

%e Some solutions for n=5:

%e   0 3 0 2     5 2 5 1     3 0 4 0     1 4 1 4     5 1 5 1

%e   5 2 5 1     2 5 2 4     0 3 1 3     5 2 5 2     1 3 1 3

%e   0 3 0 2     4 1 4 0     4 1 5 1     0 3 0 3     5 1 5 1

%e   5 2 5 1     0 3 0 2     0 3 1 3     5 2 5 2     2 4 2 4

%e   0 3 0 2     4 1 4 0     3 0 4 0     2 5 2 5     5 1 5 1

%e   5 2 5 1     0 3 0 2     2 5 3 5     4 1 4 1     0 2 0 2

%K nonn

%O 1,1

%A _R. H. Hardin_, Jan 05 2014