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A252071 Number of (n+2)X(4+2) 0..2 arrays with every 3X3 subblock row, column, diagonal and antidiagonal sum not equal to 0 3 or 4.

%I A252071 #6 Jun 02 2025 10:45:34
%S A252071 375,1135,5085,21862,92225,391934,1669294,7114867,30309042,129016031,
%T A252071 549319037,2339547000,9963141845,42425232250,180661430026,
%U A252071 769335984173,3276146397838,13951092432179,59409215103993,252988054381898
%N A252071 Number of (n+2)X(4+2) 0..2 arrays with every 3X3 subblock row, column, diagonal and antidiagonal sum not equal to 0 3 or 4.
%C A252071 Column 4 of A252075
%H A252071 R. H. Hardin, <a href="/A252071/b252071.txt">Table of n, a(n) for n = 1..210</a>
%F A252071 Empirical: a(n) = 2*a(n-1) +5*a(n-2) +14*a(n-3) +34*a(n-4) -16*a(n-5) -79*a(n-6) -150*a(n-7) -94*a(n-8) +581*a(n-9) +457*a(n-10) -913*a(n-11) -631*a(n-12) +692*a(n-13) +433*a(n-14) -236*a(n-15) -116*a(n-16) +72*a(n-17) -57*a(n-18) -32*a(n-19) +38*a(n-20) -15*a(n-21) +5*a(n-22) +11*a(n-23) -4*a(n-24) for n>26
%e A252071 Some solutions for n=4
%e A252071 ..2..1..2..2..1..2....2..2..2..2..1..2....1..2..2..2..2..1....2..2..2..2..2..2
%e A252071 ..1..2..2..2..2..1....2..2..2..2..2..2....2..2..2..2..2..2....2..2..2..1..2..2
%e A252071 ..2..2..2..2..2..2....2..1..2..2..2..2....2..2..2..2..2..2....2..1..2..2..2..2
%e A252071 ..2..1..2..2..2..2....2..2..2..1..2..2....1..2..2..2..2..2....2..2..2..2..2..2
%e A252071 ..2..2..2..2..2..1....2..2..2..2..2..2....2..2..2..2..2..1....1..2..2..2..2..2
%e A252071 ..2..2..2..2..2..2....1..2..2..2..1..2....2..2..2..1..2..2....2..2..2..2..2..1
%K A252071 nonn
%O A252071 1,1
%A A252071 _R. H. Hardin_, Dec 13 2014