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A243467 Number of ways 5 domicules can be placed on an n X n square.

%I A243467 #9 Jun 05 2014 18:55:59
%S A243467 0,0,0,0,33792,2307376,38049764,316687056,1756247962,7430841848,
%T A243467 25895095920,77947547416,209206118486,511919916960,1160763672124,
%U A243467 2468985096704,4973232330258,9557709330856,17631022607048,31372223986440,54066152166478,90552261553040
%N A243467 Number of ways 5 domicules can be placed on an n X n square.
%H A243467 Alois P. Heinz, <a href="/A243467/b243467.txt">Table of n, a(n) for n = 0..1000</a>
%F A243467 G.f.: 2*x^4*(465*x^11 -2767*x^10 -1161*x^9 -3873*x^8 +262965*x^7 -1067787*x^6 +1243269*x^5 +2069157*x^4 -9734826*x^3 -7263594*x^2 -967832*x -16896) / (x-1)^11.
%F A243467 a(n) = (5464830 -2069823*n -2896628*n^2 +1279635*n^3 +493090*n^4 -285192*n^5 -22560*n^6 +27360*n^7 -1600*n^8 -960*n^9 +128*n^10)/15 for n>=5, a(4) = 33792, a(n) = 0 for n<=3.
%e A243467 a(4) = 33792:
%e A243467 +-------+  +-------+
%e A243467 |o-o o  |  |  o   o|
%e A243467 |     \ |  | /    ||
%e A243467 |  o   o|  |o o o o|
%e A243467 |   \   |  |   X   |
%e A243467 |o   o o|  |  o o  |
%e A243467 ||    / |  |       |
%e A243467 |o   o  |  |  o-o  |
%e A243467 +-------+  +-------+   ... .
%p A243467 a:= n-> `if`(n<5, [0$4, 33792][n+1],((((((((((128*n-960)*n-1600)*n
%p A243467          +27360)*n-22560)*n-285192)*n+493090)*n+1279635)*n-2896628)
%p A243467          *n-2069823)*n+5464830)/15):
%p A243467 seq(a(n), n=0..30);
%Y A243467 Column k=5 of A243424.
%K A243467 nonn,easy
%O A243467 0,5
%A A243467 _Alois P. Heinz_, Jun 05 2014