1,2

The permutations of rows i anf j, followed by those of column i and j, preserve the property that (Tij=-Tji for i<j). The periods of the 405 6 X 6 matrices are: 11 times period 3, 94 times period 4, 71 times period 6 and 229 times period 12.

Wouter Meeussen, Periodic Matrices

{{-1,-1,0,0,0,0},{1,1,-1,0,0,0},{0,1,-1,0,0,0},{0,0,0,-1,-1,0},{0,0,0,1,1,-1},{0,0,0,0,1,-1}} is one of the 6 by 6 matrices.

see link.

Cf. A072148, A111485.

Sequence in context: A010842 A140710 A103296 this_sequence A007163 A050385 A123768

Adjacent sequences: A111746 A111747 A111748 this_sequence A111750 A111751 A111752

hard,nonn

Wouter Meeussen (wouter.meeussen(AT)pandora.be), Nov 19 2005