• Bruck-Ryser-Chowla theorem

Bruck-Ryser-Chowla theorem (suomeksi)

Määritelmät:

• (lb, en, math) A result on the combinatorics of block designs, stating that, if a (''v'', ''b'', ''r'', ''k'', λ)-design exists with ''v = b'' (a symmetric block design), then: (i) if ''v'' is even, then ''k'' − λ is a square; (ii) if ''v'' is odd, then the following Diophantine equation has a nontrivial solution: ''x''² − (''k'' − λ)''y''² − (−1)^(v−1)/2 λ ''z''² = 0.