what do we call numbers that cannot be arranged into 2-row arrays?
A matrix of order 2 x n.
n is the number of entires in each row.
Numbers that cannot be arranged into 2-row arrays are commonly referred to as invalid or incompatible numbers.
In the context of matrices, a matrix of order 2 x n refers to a matrix with 2 rows and n columns. The number of entries in each row is denoted by n. If a number cannot be arranged into such a matrix, it means that it cannot be evenly distributed and matched with another number in a 2-row arrangement.
For example, let's consider the number 7. It cannot be arranged into a 2-row matrix because there is no other number that can be paired with it in a 2-row arrangement. In a 2 x n matrix, we need an even number of elements to fill both rows evenly, so odd numbers like 7 would be considered invalid for this type of arrangement.