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A247124 Number of tilings of a 5 X n rectangle using n pentominoes of shapes I, U, X. 5
1, 1, 1, 2, 3, 8, 14, 21, 37, 63, 122, 221, 374, 656, 1147, 2066, 3699, 6477, 11407, 20099, 35656, 63323, 111775, 197352, 348556, 616560, 1091570, 1929721, 3410509, 6028021, 10658114, 18851012, 33331681, 58927069, 104177155, 184188343, 325686763, 575858676 (list; graph; refs; listen; history; text; internal format)
OFFSET
0,4
LINKS
Wikipedia, Pentomino
FORMULA
G.f.: see Maple program.
EXAMPLE
a(4) = 3:
._______. ._______. ._______.
| | | | | | | ._. | | ._. | |
| | | | | | |_| |_| |_| |_| |
| | | | | | |_. ._| |_. ._| |
| | | | | | | |_| | | |_| | |
|_|_|_|_| |_|_____| |_____|_| .
MAPLE
gf:= -(x-1)^2 *(x^4+x^3+x^2+x+1)^2 /
(x^15 +x^13 +x^11 -3*x^10 -2*x^8 -2*x^6 +6*x^5 +x^3 +x-1):
a:= n-> coeff(series(gf, x, n+1), x, n):
seq(a(n), n=0..50);
CROSSREFS
Sequence in context: A331820 A368855 A022951 * A171237 A173149 A128305
KEYWORD
nonn
AUTHOR
Alois P. Heinz, Nov 19 2014
STATUS
approved

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Last modified April 21 18:12 EDT 2024. Contains 371874 sequences. (Running on oeis4.)