A basic formula:
{{{
#!formula
\sigma(i) = exp(-\alpha_1(-log(\frac{i}{n})^{\alpha_2})
}}}


Making the rendered formula bigger:
{{{
#!formula
#density=200
\sigma(i) = exp(-\alpha_1(-log(\frac{i}{n})^{\alpha_2})
}}}


Indenting the formula from the left margin:
{{{
#!formula
#fleqn=1
\sigma(i) = exp(-\alpha_1(-log(\frac{i}{n})^{\alpha_2})
}}}


Centering the rendered formula on the page:
{{{
#!formula
#center=1
\sigma(i) = exp(-\alpha_1(-log(\frac{i}{n})^{\alpha_2})
}}}