|
%I #8 Feb 07 2017 17:25:40
%S 1,23,939,41813,1895145,86208957,3924499731,178682349823,
%T 8135650498647,370429531112741,16866286184557689,767950873073579951,
%U 34966119230441665595,1592067343861413081837,72489555274710984629691,3300573714050654978094583,150280779093325614402294089
%N Number of tilings of a 4 X 3n rectangle using 4n trominoes of any shape.
%H Alois P. Heinz, <a href="/A233339/b233339.txt">Table of n, a(n) for n = 0..600</a>
%H Wikipedia, <a href="https://en.wikipedia.org/wiki/Tromino">Tromino</a>
%F G.f.: (-x^14 +45*x^13 -790*x^12 +7195*x^11 -37791*x^10 +120544*x^9 -241021*x^8 +307384*x^7 -251359*x^6 +131039*x^5 -42817*x^4 +8472*x^3 -952*x^2 +53*x -1) / (x^15 -56*x^14 +1223*x^13 -13643*x^12 +87066*x^11 -338409*x^10 +836269*x^9 -1345297*x^8 +1419177*x^7 -976456*x^6 +431092*x^5 -118633*x^4 +19424*x^3 -1761*x^2 +76*x -1).
%Y Trisection of column k=4 of A233320.
%K nonn,easy
%O 0,2
%A _Alois P. Heinz_, Dec 07 2013
| 