A252383 - OEIS

%I #7 Dec 03 2018 10:54:30

%S 7109,1928,1610,1880,2310,2769,3495,4601,5840,7723,10599,13880,18792,

%T 26302,34929,47771,67413,90036,123639,175043,234308,322264,456822,

%U 612017,842271,1194529,1600872,2203667,3125871,4189728,5767848,8182190,10967441

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

%H R. H. Hardin, <a href="/A252383/b252383.txt">Table of n, a(n) for n = 1..210</a>

%F Empirical: a(n) = 4*a(n-3) -4*a(n-6) +a(n-9) for n>12.

%F Empirical g.f.: x*(7109 + 1928*x + 1610*x^2 - 26556*x^3 - 5402*x^4 - 3671*x^5 + 24411*x^6 + 3073*x^7 + 1204*x^8 - 5846*x^9 - 493*x^10 - 14*x^11) / ((1 - x)*(1 + x + x^2)*(1 - 3*x^3 + x^6)). - _Colin Barker_, Dec 03 2018

%e Some solutions for n=4:

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

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

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

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

%e ..0..0..3..0..0..3..0..0..3....0..0..3..0..0..0..3..0..0

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

%Y Column 7 of A252384.

%K nonn

%O 1,1

%A _R. H. Hardin_, Dec 17 2014