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A136102
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Triangle read by rows, in which rows give signatures for Ferrers boards fitting inside staircases coded 1, 2, 12, 360, 75600, ... (see A006939).
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2
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1, 1, 2, 1, 2, 4, 6, 12, 1, 2, 4, 6, 8, 12, 24, 30, 36, 60, 72, 120, 180, 360, 1, 2, 4, 6, 8, 12, 16, 24, 30, 36, 48, 60, 72, 120, 144, 180, 210, 216, 240, 360, 420, 32, 720, 840, 900, 1080, 1260, 1680, 1800, 2160, 2520, 3600, 5040, 5400, 6300, 7560, 10800, 12600
(list;
graph;
refs;
listen;
history;
text;
internal format)
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OFFSET
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1,3
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COMMENTS
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The number of signatures on each row is 1 2 5 14 42 132 ... cf. A000108.
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REFERENCES
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G. E. Andrews and K. Eriksson, Integer Partitions, Cambridge Univ. Press, 2004. page 22 Exer. 33.
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LINKS
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EXAMPLE
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The irregular array begins
1
1 2
1 2 4 6 12
1 2 4 6 8 12 24 30 36 60 72 120 180 360
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CROSSREFS
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KEYWORD
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easy,nonn,tabf
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AUTHOR
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STATUS
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approved
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