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 A252508 Number of (n+2)X(2+2) 0..3 arrays with every 3X3 subblock row and column sum equal to 0 2 5 6 or 7 and every 3X3 diagonal and antidiagonal sum not equal to 0 2 5 6 or 7 1

%I

%S 1515,1644,3980,9277,25197,76113,231372,698936,2121821,6483996,

%T 19881260,61024374,187473423,576442523,1773336035,5457204006,

%U 16797726720,51712080105,159214729408,490238324306,1509560349792,4648472850677

%N Number of (n+2)X(2+2) 0..3 arrays with every 3X3 subblock row and column sum equal to 0 2 5 6 or 7 and every 3X3 diagonal and antidiagonal sum not equal to 0 2 5 6 or 7

%C Column 2 of A252514

%H R. H. Hardin, <a href="/A252508/b252508.txt">Table of n, a(n) for n = 1..210</a>

%F Empirical: a(n) = 2*a(n-1) +2*a(n-2) +28*a(n-3) -46*a(n-4) -50*a(n-5) -302*a(n-6) +339*a(n-7) +444*a(n-8) +1659*a(n-9) -708*a(n-10) -1726*a(n-11) -5313*a(n-12) -1724*a(n-13) +2968*a(n-14) +10952*a(n-15) +9601*a(n-16) -1890*a(n-17) -15584*a(n-18) -17207*a(n-19) -452*a(n-20) +16151*a(n-21) +18538*a(n-22) +1742*a(n-23) -12916*a(n-24) -15168*a(n-25) -2082*a(n-26) +8130*a(n-27) +9975*a(n-28) +1924*a(n-29) -3684*a(n-30) -4042*a(n-31) -880*a(n-32) +880*a(n-33) +440*a(n-34) for n>41

%e Some solutions for n=4

%e ..2..3..1..2....3..2..2..1....3..1..3..2....1..3..1..1....3..1..2..2

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

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

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

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

%e ..2..1..2..2....2..3..1..3....2..3..1..2....1..3..1..3....2..3..2..2

%K nonn

%O 1,1

%A _R. H. Hardin_, Dec 18 2014

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Last modified January 25 04:34 EST 2022. Contains 350565 sequences. (Running on oeis4.)