OFFSET
0,2
LINKS
Alois P. Heinz, Table of n, a(n) for n = 0..200
David A. Klarner and Spyros S. Magliveras, The number of tilings of a block with blocks, European Journal of Combinatorics 9 (1988), 317-330.
Joshua Smith and Helena Verrill, On dividing rectangles into rectangles
FORMULA
G.f.: see Maple program.
MAPLE
gf:= (916798938728006656*x^20 -3962057190907156288*x^19 +7644699117821849592*x^18 -8795707489604640136*x^17 +6787540243858479914*x^16 -3741365942249935792*x^15 +1530293206620422033*x^14 -475918767335413756*x^13
+114321113226304761*x^12 -21415445169034874*x^11 +3143712388922139*x^10 -361909626897452*x^9 +32569667881308*x^8 -2274379347082*x^7 +121717789540*x^6 -4898404600*x^5 +144102468*x^4 -2968032*x^3 +39908*x^2 -308*x +1)/
(3488260147244630016*x^20 -13785403213649739264*x^19 +24571927550599277952*x^18 -26305901575283773400*x^17 +18988035581731414180*x^16 -9828185761768234778*x^15
+3785664669818771697*x^14 -1111033817019987980*x^13 +252212834590208135*x^12 -44688005447169948*x^11 +6207093806210985*x^10 -676048684437666*x^9 +57526055007906*x^8 -3794064844276*x^7 +191447789306*x^6 -7247125678*x^5 +199881354*x^4 -3842502*x^3 +47924*x^2 -340*x +1):
a:= n-> coeff(series(gf, x, n+1), x, n):
seq(a(n), n=0..20);
CROSSREFS
KEYWORD
nonn
AUTHOR
Alois P. Heinz, Dec 10 2012
STATUS
approved