>> x=dsolve('Dx=0.12*(1-x/286)*x-2.014*exp(-0.1491*t)*x');
x=vpa(x(2))
x =
1/(C4/exp(0.12*t + 13.507712944332662642521797451375/exp(t)^(1491/10000)) + (0.00041958041958041958041958041958042*numeric::int(exp(1/exp(t)^(1491/10000))^(20140/1491)*exp(t)^(3/25), t))/exp(0.12*t + 13.507712944332662642521797451375/exp(t)^(1491/10000)))
>>