OFFSET
0,3
COMMENTS
The shapes of the tiles are:
._.
._. | |
._. | | | |
._. | |_. | |_._. | |_._._.
|_| |___| |_____| |_______| ... .
LINKS
Alois P. Heinz, Table of n, a(n) for n = 0..1000
Wikipedia, Polyomino
Index entries for linear recurrences with constant coefficients, signature (1,10,36,93,240,392,551,576,361,324,58,58,57,-76,50,-10).
FORMULA
G.f.: (2*x^11 -8*x^10 +4*x^9 -7*x^8 -18*x^7 -29*x^6 -32*x^5 -20*x^4 -10*x^3 -3*x^2+1) / (10*x^16 -50*x^15 +76*x^14 -57*x^13 -58*x^12 -58*x^11 -324*x^10 -361*x^9 -576*x^8 -551*x^7 -392*x^6 -240*x^5 -93*x^4 -36*x^3 -10*x^2 -x+1).
CROSSREFS
KEYWORD
nonn,easy
AUTHOR
Alois P. Heinz, Dec 12 2018
STATUS
approved