Z := (s1,s2,s3,s4) ->(s1^6+8*s3^2+9*s1^2*s2^2+6*s2*s4)/24;

Zio2JkkjczFHNiJJI3MyR0YlSSNzM0dGJUkjczRHRiVGJTYkSSlvcGVyYXRvckdGJUkmYXJyb3dHRiVGJSwqKiQ5JCIiJyMiIiIiI0MqJDkmIiIjI0YxIiIkKiZGLkY1OSVGNSNGNyIiKSomRjlGMTknRjEjRjEiIiVGJUYlRiU=

a := t -> 1+t;

Zio2I0kidEc2IkYlNiRJKW9wZXJhdG9yR0YlSSZhcnJvd0dGJUYlLCYiIiJGKjkkRipGJUYlRiU=

Z(a(t),a(t^2),a(t^3),a(t^4));

LCoqJCwmIiIiRiVJInRHNiJGJSIiJyNGJSIjQyokLCZGJUYlKiRGJiIiJEYlIiIjI0YlRi4qJkYkRi8sJkYlRiUqJEYmRi9GJUYvI0YuIiIpKiZGMkYlLCZGJUYlKiRGJiIiJUYlRiUjRiVGOQ==

expand(%);

LDAiIiJGI0kidEc2IkYjKiRGJCIiI0YnKiRGJCIiJEYpKiRGJCIiJUYnKiRGJCIiJkYjKiRGJCIiJ0Yj

subs(t=1,%);

IiM2