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A201127
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Maximum water retention of a semi-magic square of order n.
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2
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OFFSET
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3,1
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COMMENTS
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The same rules as for A201126 apply, but with the magic conditions for both diagonals of the number square removed.
a(10) >= 2280. - Hugo Pfoertner, May 19 2012
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LINKS
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Table of n, a(n) for n=3..9.
Hugo Pfoertner, 3X3 Semi-magic square retaining 4 units of water
Hugo Pfoertner, 4X4 Semi-magic square retaining 22 units of water
Walter Trump, 5X5 Semi-magic square retaining 78 units of water
Hugo Pfoertner, 6X6 Semi-magic square retaining 199 units of water
Hugo Pfoertner, 7X7 Semi-magic square retaining 424 units of water
Hugo Pfoertner, 8X8 Semi-magic square retaining 814 units of water
Hugo Pfoertner, 9X9 Semi-magic square retaining 1410 units of water
Wikipedia, Water retention on mathematical surfaces
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EXAMPLE
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(7 6 2)
(5 1 9)
(3 8 4)
is a semi-magic square. The mid-side bricks with heights 6, 5, 9, 8 form a wall around the central hole with bottom height 1. Water poured upon the square will fill the central pond until overflowing via the left brick of height 5. Thus 4 units of water will be retained.
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CROSSREFS
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Cf. A201126 (water retention of magic squares).
Sequence in context: A086863 A052149 A062966 * A078155 A096167 A060453
Adjacent sequences: A201124 A201125 A201126 * A201128 A201129 A201130
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KEYWORD
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nonn,hard,nice
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AUTHOR
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Hugo Pfoertner, Dec 03 2011
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STATUS
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approved
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