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Search: id:A123821
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| A123821 |
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Number of ways to build a contiguous building with n LEGO blocks of size 2 X 2 on top of a fixed block of the same size. |
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+0
1
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| 9, 97, 1349, 20288, 329707, 5574248, 97506021, 1747201171, 31923371982, 592403479154
(list; graph; listen)
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OFFSET
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1,1
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COMMENT
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The base block is not counted among the n, and must be the only block in the bottom layer of the building
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REFERENCES
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M. Abrahamsen and S. Eilers, Efficient counting of LEGO buildings, in preparation
B. Durhuus and S. Eilers, On the entropy of LEGO, arXiv:math.CO/0504039
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LINKS
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S. Eilers, LEGO counts
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CROSSREFS
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Sequence in context: A069636 A069621 A083077 this_sequence A145509 A098782 A076758
Adjacent sequences: A123818 A123819 A123820 this_sequence A123822 A123823 A123824
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KEYWORD
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nonn,hard
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AUTHOR
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Soren Eilers (eilers(AT)math.ku.dk), Oct 29 2006
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