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%I #6 Jun 20 2022 18:59:00
%S 4192,12464,33560,116168,360760,1349336,4577624,17961560,64580152,
%T 261840344,980480600,4070568728,15709810360,66384051416,262296459224,
%U 1123428836120,4523517191992,19577976359384,80058579242840
%N Number of (n+1) X (3+1) 0..7 arrays with every 2 X 2 subblock having its diagonal sum differing from its antidiagonal sum by 7 (constant-stress 1 X 1 tilings).
%H R. H. Hardin, <a href="/A234723/b234723.txt">Table of n, a(n) for n = 1..210</a>
%F Empirical: a(n) = 4*a(n-1) +137*a(n-2) -560*a(n-3) -8456*a(n-4) +35504*a(n-5) +310702*a(n-6) -1349320*a(n-7) -7561533*a(n-8) +34294092*a(n-9) +128206281*a(n-10) -615707400*a(n-11) -1548288698*a(n-12) +8040276992*a(n-13) +13333179376*a(n-14) -77453548480*a(n-15) -79946374816*a(n-16) +552146144704*a(n-17) +309222145232*a(n-18) -2893327015040*a(n-19) -567224779296*a(n-20) +10948880162304*a(n-21) -974085452928*a(n-22) -28950298675200*a(n-23) +9103597862400*a(n-24) +50436504576000*a(n-25) -24908850432000*a(n-26) -51674112000000*a(n-27) +32903055360000*a(n-28) +23410114560000*a(n-29) -17557585920000*a(n-30).
%e Some solutions for n=4:
%e 5 3 7 4 1 4 2 4 1 5 1 3 4 5 4 7 0 5 0 3
%e 0 5 2 6 4 0 5 0 5 2 5 0 7 1 7 3 4 2 4 0
%e 3 1 5 2 4 7 5 7 1 5 1 3 3 4 3 6 0 5 0 3
%e 1 6 3 7 6 2 7 2 7 4 7 2 6 0 6 2 4 2 4 0
%e 3 1 5 2 2 5 3 5 0 4 0 2 3 4 3 6 2 7 2 5
%Y Column 3 of A234728.
%K nonn
%O 1,1
%A _R. H. Hardin_, Dec 30 2013
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