These sequences, usually called programs or, generally, software, are the base of control of hardware designs. Further we will call them algorithms. Frequently such algorithms are the result of original design, a new implementation of a formula or the improvement of an existing one. In a first approach people may consider that such a design could be patented. However this is not the case if we look at the body of law and the peculiar nature of algorithms.
Patents suppose a design for a purpose.
Algorithms are abstractions without any purpose. They are the pure combination of numbers and logical signals. Taken appart, these algorithms are nothing, as combining them in other way and adding some others may help to produce a sound on your speaker or turn your on your washing machine. Besides different algorithms may be used for one and the same purpose. The most flagrant case stays in front of anyone with a keyboard and a mouse.