MathJax supports equation numbering, but only if using TeX input.
This is a workaround for AsciiMath input:
⟪ x = (-b +- sqrt(b^2-4ac))/(2a) .⟫
⟪ e = m c^2 ⟫
⟪ (1) ⟫ ⟪ a^2 + b^2 = c^2 ↔ c = +- sqrt(a^2 + b^2) ⟫
⟪ sum_(i=1)^n i^3 = ((n(n+1))/2)^2 ⟫
⟪ (2) ⟫ ⟪ ( (a_11, a_12, a_13 ), (a_21, a_22, a_23), (a_31, a_32, a_33) ) · ( (x_1), (x_2), (x_3) ) = ( (b_1), (b_2), (b_3) ) ⟫
⟪x! = { (1 , if x le 1 ","), (x*(x-1)! , if x ge 2 ".") :}⟫
standard.js contains:
MathJax.Hub.Config({ asciimath2jax: { delimiters: [ ['\u27ea', '\u27eb'] ] } });
See page source.