login
This site is supported by donations to The OEIS Foundation.

 

Logo

Annual Appeal: Please make a donation (tax deductible in USA) to keep the OEIS running. Over 5000 articles have referenced us, often saying "we discovered this result with the help of the OEIS".

Hints
(Greetings from The On-Line Encyclopedia of Integer Sequences!)
A201127 Maximum water retention of a semi-magic square of order n. 4
4, 22, 78, 199, 424, 814, 1410 (list; graph; refs; listen; history; text; internal format)
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

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

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: A241689 A052149 A062966 * A259709 A078155 A237530

Adjacent sequences:  A201124 A201125 A201126 * A201128 A201129 A201130

KEYWORD

nonn,hard,nice

AUTHOR

Hugo Pfoertner, Dec 03 2011

STATUS

approved

Lookup | Welcome | Wiki | Register | Music | Plot 2 | Demos | Index | Browse | More | WebCam
Contribute new seq. or comment | Format | Style Sheet | Transforms | Superseeker | Recent | More pages
The OEIS Community | Maintained by The OEIS Foundation Inc.

License Agreements, Terms of Use, Privacy Policy .

Last modified December 3 21:14 EST 2016. Contains 278745 sequences.