%I #4 Dec 17 2013 16:10:43
%S 640,3944,22632,138132,807964,4908404,28936484,175407492,1039210048,
%T 6291984872,37411050288,226333090864,1349436837188,8159273967724,
%U 48752105141528,294639966341512,1763518515517052,10653925639599432
%N Number of (n+1)X(2+1) 0..7 arrays with every 2X2 subblock having the sum of the squares of the edge differences equal to 30, and no two adjacent values equal
%C Column 2 of A233917
%H R. H. Hardin, <a href="/A233911/b233911.txt">Table of n, a(n) for n = 1..210</a>
%F Empirical: a(n) = 4*a(n-1) +122*a(n-2) -461*a(n-3) -6376*a(n-4) +22883*a(n-5) +188152*a(n-6) -648596*a(n-7) -3478827*a(n-8) +11715412*a(n-9) +42308852*a(n-10) -142371381*a(n-11) -345931578*a(n-12) +1197824103*a(n-13) +1908669954*a(n-14) -7078856586*a(n-15) -6995027392*a(n-16) +29551303874*a(n-17) +16143386244*a(n-18) -87052258170*a(n-19) -19433628990*a(n-20) +179619345422*a(n-21) -2128109482*a(n-22) -255775086626*a(n-23) +46189589396*a(n-24) +245226941694*a(n-25) -73044737386*a(n-26) -152167442028*a(n-27) +56827325500*a(n-28) +57294922304*a(n-29) -23672423108*a(n-30) -11706249412*a(n-31) +4940867468*a(n-32) +1040756704*a(n-33) -439680112*a(n-34) -20118176*a(n-35) +11155520*a(n-36) -250624*a(n-37) -14592*a(n-38)
%e Some solutions for n=4
%e ..2..0..2....2..6..2....0..4..3....1..4..1....6..5..6....0..1..0....0..3..7
%e ..5..4..1....4..7..5....2..1..5....5..6..2....4..1..4....3..5..3....4..5..4
%e ..2..0..2....2..6..2....6..3..2....1..3..1....3..5..3....0..1..0....6..2..6
%e ..1..4..1....5..7..4....5..1..5....5..6..5....4..1..4....3..5..2....7..5..7
%e ..5..3..5....6..3..2....3..4..6....7..3..7....3..5..3....7..4..6....3..6..3
%K nonn
%O 1,1
%A _R. H. Hardin_, Dec 17 2013