Equally spaced polynomial

An equally spaced polynomial (ESP) is a polynomial used in finite fields, specifically GF(2) (binary).

An s-ESP of degree sm can be written as:

${\displaystyle ESP(x)=\sum _{i=0}^{m}x^{si}}$ for ${\displaystyle i=0,1,\ldots ,m}$

or

${\displaystyle ESP(x)=x^{sm}+x^{s(m-1)}+\cdots +x^{s}+1.}$