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A201127
Maximum water retention of a semi-magic square of order n.
4
4, 22, 78, 199, 424, 814, 1410
OFFSET
3,1
COMMENTS
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
EXAMPLE
(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.
CROSSREFS
Cf. A201126 (water retention of magic squares).
Sequence in context: A052149 A062966 A347722 * A259709 A078155 A237530
KEYWORD
nonn,hard,nice,more
AUTHOR
Hugo Pfoertner, Dec 03 2011
STATUS
approved