|
%I #8 Dec 03 2018 06:28:33
%S 130,272,822,2290,6164,17008,47094,129530,356572,982904,2707976,
%T 7459326,20550724,56618068,155978958,429715562,1183856500,3261484928,
%U 8985276082,24754144796,68196859814,187880079930,517603410590,1425980330978
%N Number of (n+2) X (2+2) 0..3 arrays with every 3 X 3 subblock row, column, diagonal and antidiagonal sum not equal to 2 3 4 6 or 7.
%H R. H. Hardin, <a href="/A252263/b252263.txt">Table of n, a(n) for n = 1..210</a>
%F Empirical: a(n) = a(n-1) + 2*a(n-2) + 6*a(n-3) + 5*a(n-4) + a(n-5) - 2*a(n-6) - 2*a(n-7) - a(n-8) for n>9.
%F Empirical g.f.: 2*x*(65 + 71*x + 145*x^2 + 72*x^3 - 26*x^4 - 79*x^5 - 52*x^6 - 16*x^7 + 7*x^8) / (1 - x - 2*x^2 - 6*x^3 - 5*x^4 - x^5 + 2*x^6 + 2*x^7 + x^8). - _Colin Barker_, Dec 03 2018
%e Some solutions for n=4:
%e ..0..0..0..0....1..0..0..0....3..2..3..3....0..1..0..0....3..3..2..3
%e ..0..0..1..0....0..0..1..0....2..3..3..2....0..0..0..0....3..3..3..2
%e ..0..0..0..0....0..0..0..0....3..3..3..3....1..0..0..0....3..3..3..3
%e ..0..1..0..0....0..0..0..0....3..3..3..3....0..0..0..0....3..3..3..3
%e ..0..0..0..1....0..0..0..0....3..3..2..3....0..0..0..0....3..3..3..2
%e ..1..0..0..0....0..1..0..0....2..3..3..3....0..0..0..0....2..3..3..3
%Y Column 2 of A252269.
%K nonn
%O 1,1
%A _R. H. Hardin_, Dec 16 2014
| 