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defintion_of_subsets [2023/03/02 19:27] – [The representative line of a magic square] minodefintion_of_subsets [2024/09/07 11:58] (current) – external edit 127.0.0.1
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 We introduce some terminologies here to divide the whole set of magic squares into small subsets. We introduce some terminologies here to divide the whole set of magic squares into small subsets.
  
-==== A magic set and its binary representation ==== +==== A magic series and its binary representation ==== 
-  * We define **magic set of order //n//** as a set of //n// distinct integers in the range //[1..n<sup>2</sup>]// whose sum is equal to the magic sum //( ( n<sup>2</sup> + 1 ) * n ) / 2//.+  * **magic series of order //n//** is a set of //n// distinct integers in the range //[1..n<sup>2</sup>]// whose sum is equal to the magic sum //( ( n<sup>2</sup> + 1 ) * n ) / 2//.
     * Examples:     * Examples:
-      * { 2, 9, 4 } is a magic set of order 3. +      * { 2, 9, 4 } is a magic series of order 3. 
-      * { 10, 7, 14, 3 } is a magic set of order 4.+      * { 10, 7, 14, 3 } is a magic series of order 4.
   * Any set of distinct positive integers { a<sub>1</sub>, a<sub>2</sub>, a<sub>3</sub> ...  } can be represented as an integer whose value is equal to 2<sup>a<sub>1</sub>-1</sup> + 2<sup>a<sub>2</sub>-1</sup> + 2<sup>a<sub>3</sub>-1</sup> + ... . We call it the binary representation of a distinct integer set.   * Any set of distinct positive integers { a<sub>1</sub>, a<sub>2</sub>, a<sub>3</sub> ...  } can be represented as an integer whose value is equal to 2<sup>a<sub>1</sub>-1</sup> + 2<sup>a<sub>2</sub>-1</sup> + 2<sup>a<sub>3</sub>-1</sup> + ... . We call it the binary representation of a distinct integer set.
     * Examples:     * Examples:
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     * We can define order on sets of distinct integers in accord with the order of their binary representation.     * We can define order on sets of distinct integers in accord with the order of their binary representation.
     * Example:     * Example:
-      * A magic set { 5, 16, 2, 11 } is larger than { 12, 1, 15, 6 } because their binary representations are 1000 0100 0001 0010 ( = 0x8412 ) and 0100 1000 0010 0001 ( = 0x4821 ), respectively, and 0x8412 > 0x4821. +      * A magic series { 5, 16, 2, 11 } is greater than { 12, 1, 15, 6 } because their binary representations are 1000 0100 0001 0010 ( = 0x8412 ) and 0100 1000 0010 0001 ( = 0x4821 ), respectively, and 0x8412 > 0x4821. 
-==== Complement of a magic set ====+==== Complement of a magic series ====
  
-If you replace each element //a// of a magic set by // n<sup>2</sup> + 1 - //, the result is also a magic set. We call the resulting set the **compliment** of the original magic set.+If you replace each element //x// of a magic series by // n<sup>2</sup> + 1 - //, the result is also a magic series. We call the resulting set the **complement** of the original magic series.
  
   * Examples in the case of order 4:   * Examples in the case of order 4:
-    * { 12, 1, 15, 6 } is the compliment of { 5, 16, 2, 11 }. +    * { 12, 1, 15, 6 } is the complement of { 5, 16, 2, 11 }. 
-    * { 7, 10, 3, 14 } is the compliment of itself.+    * { 7, 10, 3, 14 } is the complement of itself.
  
-In binary representations, the compliment of a magic set is obtained by the bit reverse manipulation.+In binary representations, the complement of a magic series is obtained by the bit reverse manipulation.
  
   * Example in the case of order 4:   * Example in the case of order 4:
-    * The compliment of 1000 0100 0001 0010 is 0100 1000 0010 0001.+    * The complement of 1000 0100 0001 0010 is 0100 1000 0010 0001.
  
-==== The representative line of a magic square ====+==== The representative magic series of a magic square ====
  
-Every row and column of a magic square always forms a magic set. We define the ** representative line ** of a magic square as **the largest magic set which forms a row, a column, compliment of a row, or compliment of a column** and classify magic squares by their representative lines. This classification is invariant under rotations, reflections, and the compliment transformation. Note that diagonal or counter-diagonal magic set are not considered the representative line.+Every row and column of a magic square is always a magic series. We define the ** representative magic series ** of a magic square as **the largest magic series which forms a row, a column, the complement of a row, or the complement of a column**. Note that diagonal magic series are not considered representative magic series.
  
 Example:  Example: 
 +The representative magic series of a magic square
 +
 +    16 12  1  5
 +      3 14 10
 +     9 13  4  8
 +      6 15 11
 +
 +is { 16, 13, 3, 2 } = 0x9006, which forms the complement of the third column.
 +
 +**We classify magic squares by their representative magic series. This classification is invariant under rotations, reflections, [[https://oeis.org/A266237|M-transformations]], and the complement transformation.
 +**
  
defintion_of_subsets.1677752828.txt.gz · Last modified: 2023/03/02 19:27 by mino

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