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arXiv · 2608.15318

A proper Euler magic matrix of order 6

Sanjit Singh Mehat
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Abstract

An Euler magic matrix is an integer matrix M with MM^t = gamma I for some gamma != 0, whose squared entries sum to gamma along both main diagonals; it is proper if its squared entries are pairwise distinct. Euler gave a proper example of order 4; M\"uller settled orders 3 (none exists) and 8; and Kominers settled order 5. We give an order-6 construction, a case not addressed by M\"uller or Kominers, exhibiting a proper Euler magic matrix of order 6 with gamma = 18500 together with a second, independent one with gamma = 43290. The proof is the explicit matrix and a finite exact verification. We also record an elementary counting bound gamma >= 2485 for proper order-6 examples.

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Sanjit Singh Mehat. 2026-08-15. A proper Euler magic matrix of order 6. https://arxiv.org/abs/2608.15318

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