cp's OEIS Frontend

A243648 Number of ways five L-tiles can be placed on an n X n square.

%I A243648 #6 Jun 08 2014 12:50:34
%S A243648 0,0,0,0,0,46,4431,73098,587149,3125278,12712329,42731866,124522115,
%T A243648 324628878,773900299,1714106922,3569586561,7053577342,13321444117,
%U A243648 24185953530,42413141575,72121174766,119308962279,192546161866,303861667221,469873699038,713211276481
%N A243648 Number of ways five L-tiles can be placed on an n X n square.
%H A243648 Alois P. Heinz, <a href="/A243648/b243648.txt">Table of n, a(n) for n = 0..1000</a>
%F A243648 G.f.: x^5*(33*x^10 -293*x^9 +504*x^8 +1350*x^7 -3422*x^6 -7274*x^5 +28906*x^4 -19186*x^3 -26887*x^2 -3925*x -46) / (x-1)^11.
%F A243648 a(n) = (n^10 -10*n^9 -25*n^8 +520*n^7 -435*n^6 -9982*n^5 +19925*n^4 +82740*n^3 -215906*n^2 -244868*n +728760) / 120 for n>=5, a(n) = 0 for n<5.
%p A243648 a:= n-> `if`(n<5, 0, ((((((((((n-10)*n-25)*n+520)*n-435)*n
%p A243648     -9982)*n+19925)*n+82740)*n-215906)*n-244868)*n+728760)/120):
%p A243648 seq(a(n), n=0..40);
%Y A243648 Column k=5 of A243608.
%K A243648 nonn,easy
%O A243648 0,6
%A A243648 _Alois P. Heinz_, Jun 08 2014