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Search: id:A019439
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| A019439 |
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Number of ways of tiling a 2 X n rectangle with dominoes and triominoes. |
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+0
1
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| 1, 2, 6, 17, 43, 108, 280, 727, 1875, 4832, 12470, 32191, 83075, 214372, 553214, 1427673, 3684333, 9507936, 24536616, 63320419, 163407771, 421697922, 1088253936, 2808400703, 7247494517, 18703234038, 48266468208, 124558777387
(list; graph; listen)
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OFFSET
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1,2
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COMMENT
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The old entry with this sequence number was a duplicate of A007737.
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REFERENCES
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Jaime Rangel-Mondragon, Polyominoes and Related Families, The Mathematica Journal, 9:3 (2005), 609-640.
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FORMULA
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G.f.: -(x^3+x-1)/(x^6-x^5-2*x^4-3*x^3-2*x+1). [From Alois P. Heinz (heinz(AT)hs-heilbronn.de), Sep 24 2009]
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MAPLE
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a:= n-> (Matrix([[1, 1, 0, 0, 1, 1]]). Matrix (6, (i, j)-> if i=j-1 then 1 elif j=1 then [2, 0, 3, 2, 1, -1][i] else 0 fi)^n)[1, 2]: seq (a(n), n=1..30); [From Alois P. Heinz (heinz(AT)hs-heilbronn.de), Sep 24 2009]
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CROSSREFS
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Sequence in context: A072077 A014833 A130104 this_sequence A018024 A000996 A020963
Adjacent sequences: A019436 A019437 A019438 this_sequence A019440 A019441 A019442
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KEYWORD
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nonn
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AUTHOR
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N. J. A. Sloane (njas(AT)research.att.com), Oct 04 2008
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EXTENSIONS
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More terms from Alois P. Heinz (heinz(AT)hs-heilbronn.de), Sep 24 2009
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