An Infinite 2-Dimensional Derangement
Leroy Quet
qq-quet at mindspring.com
Sat Feb 21 02:11:46 CET 2004
Take an infinite matrix where each positive integer occurs exactly once
in each column and in each row.
(In other words, each row is a permutation of the positive integers, and
is a derangement of every other row-permutation.)
So, if we let the first row simply be
1, 2, 3, 4, 5,...,
and then form each additional row by choosing for an element, as we move
from left to right, the lowest integer not yet in that row NOR in that
element's column, we have an easy and natural way to generate such a
matrix.
1, 2, 3, 4, 5, 6, 7, 8...
2, 1, 4, 3, 6, 5, 8, 7...
3, 4, 1, 2, 7, 8, 5, 6...
4, 3, 2, 1, 8, 7, 6, 5...
5, 6, 7, 8, 1, 2, 3, 4...
6, 5, 8, 7, 2, 1, 4, 3...
7, 8, 5, 6, 3, 4, 1, 2...
8, 7, 6, 5, 4, 3, 2, 1...
....
Now, several patterns seem to be in-evidence with the matrix as figured
so far.
So, the most general question I will ask is, what is a closed-form way to
calculate each element given only its row and column?
And, oh yeah, the diagonally-read sequence of this table is not in the
EIS.
1, 2, 2, 3, 1, 3, 4, 4, 4, 4, 5, 3, 1, 3, 5, 6, 6, 2, 2, 6, 6,...
thanks,
Leroy Quet
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