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A226373
Number of tilings of a 9 X n rectangle using integer-sided square tiles of area > 1.
2
1, 0, 0, 1, 0, 0, 19, 0, 0, 50, 17, 0, 499, 34, 2, 1932, 901, 4, 14152, 2904, 455, 66283, 37037, 1319, 420837, 158496, 33772, 2165069, 1414662, 133691, 12858197, 7114650, 1842975, 69205389, 52535381, 8951317, 398719444, 288028604, 88120788, 2192096580
OFFSET
0,7
LINKS
FORMULA
G.f.: see Maple program.
EXAMPLE
a(14) = 2:
._._._._._._._._._._._._._._. ._._._._._._._._._._._._._._.
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| | | |___|___|___|___|___|___|___|
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|_____________|_____________| | | |
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|___|___|___|___|___|___|___| |_____________|_____________|
MAPLE
a:= n-> coeff(series(-(6*x^47 -2*x^46 -6*x^45 +14*x^44 -4*x^43 -48*x^42 -7*x^41 +33*x^40 -61*x^39 -13*x^38 +62*x^37 +58*x^36 -20*x^35 -24*x^34 +30*x^33 -61*x^32 +18*x^31 +121*x^30 +86*x^29 -79*x^28 +270*x^27 +123*x^26 -134*x^25 -435*x^24 -113*x^23 +106*x^22 -388*x^21 -83*x^20 +66*x^19 +367*x^18 +60*x^17
-38*x^16 +189*x^15 +22*x^14 -8*x^13 -130*x^12 -13*x^11 +4*x^10 -36*x^9 -2*x^8 +20*x^6 +x^5 +2*x^3 -1) / (2*x^57 -4*x^55 +4*x^54 +2*x^53 -20*x^52 -75*x^51 +28*x^50 +18*x^49 -156*x^48 +89*x^47 +182*x^46 +88*x^45 -129*x^44 +225*x^43 -102*x^42 -53*x^41 -82*x^40 +346*x^39 +176*x^38 -573*x^37 -357*x^36 -242*x^35
+563*x^34 -583*x^33 +460*x^32 -121*x^31 +700*x^30 +8*x^29 +56*x^28 -2274*x^27 -872*x^26 +949*x^25 +1358*x^24 +368*x^23 -530*x^22 +2250*x^21 +394*x^20 -412*x^19 -1366*x^18 -200*x^17 +204*x^16 -694*x^15 -60*x^14 +46*x^13 +386*x^12 +29*x^11 -21*x^10 +79*x^9 +3*x^8 -36*x^6 -x^5 -3*x^3 +1), x, n+1), x, n):
seq(a(n), n=0..50);
CROSSREFS
Column k=9 of A226206.
Sequence in context: A271975 A186729 A340650 * A240952 A221749 A055967
KEYWORD
nonn,easy
AUTHOR
Alois P. Heinz, Jun 05 2013
STATUS
approved