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A109130
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Magic constant of smallest order-n perfect magic cube.
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0
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1, 0, 0, 0, 315, 651, 1204, 2052, 3285, 5005, 7326, 10374, 14287, 19215, 25320, 32776, 41769, 52497, 65170, 80010, 97251, 117139, 139932, 165900, 195325, 228501, 265734, 307342, 353655, 405015, 461776, 524304, 592977, 668185, 750330, 839826
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OFFSET
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1,5
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COMMENTS
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A perfect magic cube is one such that each square extracted from it is magic. (The sum of columns, rows, diagonals of each face and diagonals of opposite vertices all sum up to the same constant).
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REFERENCES
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C. Boyer, "Le plus petit cube magique parfait", La Recherche pp. 48-50 March 2004 Paris.
N. Revoy, "Cube magique", Science et Vie, pp. 66-69 March 2004, Paris.
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LINKS
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FORMULA
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a(n)=(n^4 + n)/2 for n=1 and n>=5.
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EXAMPLE
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a(5)=315 implies each of the 109 {=A056107(5+1)} lines crossing 5 cells of the side 5 perfect magic cube numbered 1 through 5^3 adds up to 315.
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CROSSREFS
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KEYWORD
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nonn
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AUTHOR
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EXTENSIONS
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STATUS
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approved
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