# descending order

A sequence or arbitrary ordered set or one-dimensional array of numbers, $a$, is said to be in if each $a_{i}\geq a_{i+1}$. For example, the aliquot sequence of 259 is in descending order: 45, 33, 15, 9, 4, 3, 1, 0, 0, 0 … The aliquot sequence starting at 60, however, is not in descending order: 108, 172, 136, 134, 70, 74, 40, 50, 43, 1, 0, 0, 0 …

In a trivial sense, the sequence of values of the sign function multiplied by -1 is in descending order: … 1, 1, 1, 0, –1, –1, –1… When each $a_{i}>a_{i+1}$ in the sequence, set or array, then it can be said to be in strictly descending order.

Title descending order DescendingOrder 2013-03-22 16:06:49 2013-03-22 16:06:49 CompositeFan (12809) CompositeFan (12809) 5 CompositeFan (12809) Definition msc 06A99 AscendingOrder strictly descending order