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A247127
Number of tilings of a 5 X n rectangle using n pentominoes of shapes V, U, X, N.
2
1, 0, 0, 1, 4, 0, 9, 8, 24, 17, 78, 64, 227, 212, 664, 699, 2004, 2220, 6033, 7196, 18112, 22859, 54882, 72560, 166251, 229284, 505632, 721421, 1540532, 2264668, 4702135, 7092742, 14376450, 22165709, 44024116, 69154334, 134973515, 215459398, 414268932
OFFSET
0,5
LINKS
Wikipedia, Pentomino
FORMULA
G.f.: see Maple program.
MAPLE
gf:= -(4*x^18 +4*x^17 -8*x^16 -3*x^15 -9*x^14 +2*x^13 -3*x^12 +5*x^11 -7*x^10 +x^9 -7*x^8 -x^6 -2*x^5 -x^3+1) / (32*x^26 +32*x^25 -32*x^24 +8*x^23 -120*x^22 +12*x^21 -124*x^20 +36*x^19 -123*x^18 +35*x^17 -106*x^16 +20*x^15 -62*x^14 -23*x^13 -22*x^12 -36*x^11 +5*x^10 -18*x^9 +13*x^8 -4*x^7 +8*x^6 +2*x^5 +4*x^4 +2*x^3-1):
a:= n-> coeff(series(gf, x, n+1), x, n):
seq(a(n), n=0..50);
CROSSREFS
KEYWORD
nonn
AUTHOR
Alois P. Heinz, Nov 19 2014
STATUS
approved