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Search: id:A072843
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| A072843 |
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O'Halloran numbers: even integers which cannot be the surface area of a cuboid with integer-length sides. |
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+0
1
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| 8, 12, 20, 36, 44, 60, 84, 116, 140, 156, 204, 260, 380, 420, 660, 924
(list; graph; listen)
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OFFSET
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0,1
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COMMENT
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Named to commemorate the founder of the Australian Mathematics Competition, Peter O'Halloran, shortly before his untimely death in 1994.
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REFERENCES
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A. Edwards - "The Cellars At The Hotel Mathematics" - Keynote article in "Mathematics - Imagine The Possibilities" (Conference handbook for the MAV conference - 1997) pp. 18-19
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EXAMPLE
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The total surface areas of the smallest possible cuboids (1.1.1), (2.1.1),(2.2.1),(3.1.1) and (4.1.1) are, respectively, 6, 10, 16, 14 and 18 square units, assuming their side lengths are whole numbers. Thus the first two O'Halloran Numbers are 8 and 12 as they do not appear on this list of areas.
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CROSSREFS
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Adjacent sequences: A072840 A072841 A072842 this_sequence A072844 A072845 A072846
Sequence in context: A105936 A084488 A001749 this_sequence A072902 A105571 A141616
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KEYWORD
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fini,full,nonn
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AUTHOR
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Andy Edwards (AndynGen(AT)aol.com), Jul 24 2002
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