Find a diŽerential equation whose solution is the two parameter fam-ily of curves lny=c1*x^2+c2.

I've gotten this far:

y= e^(c1*x^2+c2)

y'= 2*c1*x* (e^(c1*x^2+c2).

I also found y''. But for the world of it I cannot figure out the differential equation from y, y' and y''.

Really appreciate your help!