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
LINKS
Hugo Pfoertner, 3 X 3 Semi-magic square retaining 4 units of water
Hugo Pfoertner, 4 X 4 Semi-magic square retaining 22 units of water
Walter Trump, 5 X 5 Semi-magic square retaining 78 units of water
Hugo Pfoertner, 6 X 6 Semi-magic square retaining 199 units of water
Hugo Pfoertner, 7 X 7 Semi-magic square retaining 424 units of water
Hugo Pfoertner, 8 X 8 Semi-magic square retaining 814 units of water
Hugo Pfoertner, 9 X 9 Semi-magic square retaining 1410 units of water
Wikipedia, Water retention on mathematical surfaces
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
KEYWORD
nonn,hard,nice,more
AUTHOR
Hugo Pfoertner, Dec 03 2011
STATUS
approved