Bimagic squares, 10th and 11th-order


Fredrik Jansson (Turku 1982 - )

Numerous 8th and 9th-order bimagic squares have been constructed since Pfeffermann, a century ago, but none 10th or 11th-order have been successfully constructed.

The first known 10th-order bimagic square was constructed in January 2004 by Fredrik Jansson, Finland. Fredrik is a young student, currently a second year physics student at the Åbo Akademi University, in Turku. He also studies mathematics and computer science.

First known bimagic square of order 10,
by Fredrik Jansson, January 2004

2

19

70

1

66

74

73

60

68

72

58

77

15

3

65

4

67

69

71

76

62

63

82

75

61

59

79

6

5

13

49

18

14

78

98

40

25

96

43

44

94

41

27

42

35

91

21

95

37

22

93

39

23

38

31

90

33

30

29

99

34

100

36

83

45

24

26

28

97

32

8

85

64

57

7

56

80

48

16

84

54

11

86

47

87

12

92

20

50

46

51

52

88

81

10

55

9

53

89

17

He used the fact that there are so many series of order 10, as mentioned in the old version of this page: if we list the series of 10 different integers, from 1 to 100, having for magic sums S1 =  505, and S2 =  33,835, we find 24,643,236 series. And if we limit ourselves to series having the number 100 among their 10 integers, there are still 2,240,776 series! Thinking of these enormous numbers, the probability was very high that 10th-order bimagic squares existed... but nobody had succeeded. Congratulations to Fredrik!

Here are other bimagic squares of order 10, constructed later, in 2006 and 2007:

Bimagic square of order 10,
by Christian Boyer, October 2006

81

44

41

63

88

3

49

53

1

82

26

38

92

90

25

45

42

62

2

83

96

97

31

46

68

8

22

24

57

56

16

100

9

75

11

71

43

54

65

61

28

48

7

51

34

91

95

59

77

15

13

27

87

14

60

89

55

64

79

17

72

36

52

18

86

47

23

6

66

99

58

10

74

30

84

50

5

94

67

33

80

76

39

98

37

32

78

4

21

40

35

29

73

20

12

69

93

85

70

19


Bimagic square of order 10,
by Pan Fengchu, September 2007

89

51

52

88

53

55

10

9

17

81

59

82

62

61

13

6

79

75

63

5

1

2

66

68

72

74

70

73

60

19

42

41

27

22

91

21

35

37

95

94

57

80

64

8

16

85

56

48

7

84

54

20

86

92

11

50

12

87

46

47

78

98

14

40

43

18

44

96

25

49

3

65

4

77

71

58

76

15

67

69

39

30

33

23

90

38

99

31

93

29

83

36

97

26

45

100

24

34

32

28

G. Pfeffermann, again him, and again in Les Tablettes du Chercheur, had published 3 non-normal bimagic squares of order 10, in 1894 and 1896. Here is the last published, which uses non-consecutive integers between 1 and 137.

Non-normal bimagic square of order 10,
by G. Pfeffermann, March 1st 1896

24

133

108

51

129

19

71

42

13

100

130

28

35

134

72

52

14

111

94

20

1

7

84

113

106

40

37

64

117

121

107

65

2

18

23

99

128

122

85

41

83

112

116

29

15

135

95

6

36

63

75

102

132

43

3

123

109

22

26

55

97

53

16

10

39

115

120

136

73

31

17

21

74

101

98

32

25

54

131

137

118

44

27

124

86

66

4

103

110

8

38

125

96

67

119

9

87

30

5

114

11th-order bimagic squares

Also in January 2004, only 18 days later than his 10th-order bimagic square, Fredrik Jansson constructed the first 11th-order bimagic square, using similar methods (combining bimagic series).

First known bimagic square of order 11,
by Fredrik Jansson, January 2004

84

80

88

2

82

10

81

74

1

86

83

53

114

118

35

47

26

27

55

58

113

25

119

45

40

51

116

38

42

29

33

117

41

21

109

20

66

60

37

115

111

54

59

19

69

87

85

4

79

89

94

8

3

75

78

39

15

14

105

96

64

103

61

98

63

13

121

34

44

57

46

120

30

48

108

31

32

73

91

90

71

7

92

95

5

76

6

65

52

36

17

107

16

104

18

77

70

62

112

12

11

99

72

100

67

43

97

68

9

93

28

49

56

101

22

24

23

106

102

50

110

Another 11th-order bimagic square was constructed later by Chen Mutian, China, in May 2005. This square is symmetrical around its centre, meaning that two cells symmetrical (around the centre) have always the same sum, here 122. An interesting consequence is that the 4 lines of 11 numbers going through the centre are trimagic: the central row, the central column, and the 2 diagonals.

Symmetrical bimagic square of order 11,
by Chen Mutian, May 2005.
The two diagonals, the central row and the central column are trimagic.

9

19

65

30

72

76

106

121

93

47

33

101

97

88

20

56

4

27

74

70

108

26

86

87

51

109

112

41

12

54

3

37

79

84

11

58

94

8

91

40

78

120

24

63

6

104

23

115

22

105

69

60

55

73

39

15

32

117

80

45

61

77

42

5

90

107

83

49

67

62

53

17

100

7

99

18

116

59

98

2

44

82

31

114

28

64

111

38

43

85

119

68

110

81

10

13

71

35

36

96

14

52

48

95

118

66

102

34

25

21

89

75

29

1

16

46

50

92

57

103

113


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