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A284385
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Number of fixed convex n-iamonds (or polyiamonds with n cells).
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1
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2, 3, 6, 8, 6, 7, 12, 15, 8, 9, 18, 18, 8, 15, 24, 23, 12, 12, 24, 30, 12, 17, 36, 31, 14, 21, 30, 30, 18, 24, 42, 42, 14, 21, 48, 38, 14, 33, 48, 45, 24, 18, 42, 54, 24, 35, 66, 48, 20, 36, 48, 44, 24, 40, 72, 63, 18, 27, 72, 60, 26, 51, 66, 62, 36, 30, 60
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refs;
listen;
history;
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OFFSET
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1,1
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COMMENTS
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Also, the number of ways to write n as p^2-q^2-r^2-s^2 with 0 <= min(q, r, s) and max(q, r, s) < n and max(q+r, r+s, s+q) <= n.
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LINKS
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EXAMPLE
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See Links section.
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CROSSREFS
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KEYWORD
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nonn
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AUTHOR
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STATUS
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approved
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