# Multimagic square

In mathematics, a P-multimagic square (also known as a satanic square) is a magic square that remains magic even if all its numbers are replaced by their kth power for 1 ≤ kP. Thus, a magic square is bimagic if it is 2-multimagic, and trimagic if it is 3-multimagic; tetramagic for 4-multimagic; and pentamagic for a 5-multimagic square.

## Constants for normal squares

If the squares are normal, the constant for the power-squares can be determined as follows:

Bimagic series totals for bimagic squares are also linked to the square-pyramidal number sequence is as follows :-
Squares 0, 1, 4, 9, 16, 25, 36, 49, .... (sequence A000290 in OEIS)
Sum of Squares 0, 1, 5, 14, 30, 55, 91, 140, 204, 285, ... (sequence A000330 in OEIS) )number of units in a square-based pyramid)
The bimagic series is the 1st, 4th, 9th in this series (divided by 1, 2, 3, n) etc. so values for the rows and columns in order-1, order-2, order-3 Bimagic squares would be 1, 15, 95, 374, 1105, 2701, 5775, 11180, ... (sequence A052459 in OEIS)

The trimagic series would be related in the same way to the hyper-pyramidal sequence of nested cubes.
Cubes 0, 1, 8, 27, 64, 125, 216, ... (sequence A000578 in OEIS)
Sum of Cubes 0, 1, 9, 36, 100, ... (sequence A000537 in OEIS)
Value for Trimagic squares 1, 50, 675, 4624, ... (sequence A052460 in OEIS)

Similarly the tetramagic sequence
4-Power 0, 1, 16, 81, 256, 625, 1296, ... (sequence A000583 in OEIS)
Sum of 4-Power 0, 1, 17, 98, 354, 979, 2275, ... (sequence A000538 in OEIS)
Sums for Tetramagic squares 0, 1, 177, ... (sequence A052461 in OEIS)

## Bimagic square

The first known bimagic square has order 8 and magic constant 260 and a bimagic constant of 11180.

It has been conjectured by Bensen and Jacoby that no nontrivial[clarification needed] bimagic squares of order less than 8 exist. This was shown for magic squares containing the elements 1 to n2 by Boyer and Trump.

However, J. R. Hendricks was able to show in 1998 that no bimagic square of order 3 exists, save for the trivial bimagic square containing the same number nine times. The proof is fairly simple: let the following be our bimagic square.

 a b c d e f g h i

It is well known that a property of magic squares is that $a+i=2e$. Similarly, $a^2+i^2=2e^2$. Therefore $(a-i)^2=2(a^2+i^2)-(a+i)^2=4e^2-4e^2=0$. It follows that $a=e=i$. The same holds for all lines going through the center.

For 4×4 squares, Luke Pebody was able to show by similar methods that the only 4×4 bimagic squares (up to symmetry) are of the form

 a b c d c d a b d c b a b a d c

or

 a a b b b b a a a a b b b b a a

An 8×8 bimagic square.

 16 41 36 5 27 62 55 18 26 63 54 19 13 44 33 8 1 40 45 12 22 51 58 31 23 50 59 30 4 37 48 9 38 3 10 47 49 24 29 60 52 21 32 57 39 2 11 46 43 14 7 34 64 25 20 53 61 28 17 56 42 15 6 35

Nontrivial bimagic squares are now (2010) known for any order from eight to 64. Li Wen of China created the first known bimagic squares of orders 34, 37, 38, 41, 43, 46, 47, 53, 58, 59, 61, 62 filling the gaps of the last unknown orders.

## Trimagic square

Trimagic squares of orders 12, 32, 64, 81 and 128 have been discovered so far; the only known trimagic square of order 12, given below, was found in June 2002 by German mathematician Walter Trump.

 1 22 33 41 62 66 79 83 104 112 123 144 9 119 45 115 107 93 52 38 30 100 26 136 75 141 35 48 57 14 131 88 97 110 4 70 74 8 106 49 12 43 102 133 96 39 137 71 140 101 124 42 60 37 108 85 103 21 44 5 122 76 142 86 67 126 19 78 59 3 69 23 55 27 95 135 130 89 56 15 10 50 118 90 132 117 68 91 11 99 46 134 54 77 28 13 73 64 2 121 109 32 113 36 24 143 81 72 58 98 84 116 138 16 129 7 29 61 47 87 80 34 105 6 92 127 18 53 139 40 111 65 51 63 31 20 25 128 17 120 125 114 82 94

## Higher order

The first 4-magic square, of order 512, was constructed in May 2001 by André Viricel and Christian Boyer.

The first 5-magic square, of order 1024 arrived about one month later, in June 2001 again by Viricel and Boyer. They also presented a smaller 4-magic square of order 256 in January 2003. Another 5-magic square, of order 729, was constructed in June 2003 by Chinese mathematician Li Wen.