Hello to everbody,
I wave an equation with datas and want to regress in non linear form with plot.
Would you help me to solve the equation bellow by any softwares, please?

The data, the equation and parameters are given bellow. I want to fit the data to non-linear equation to find D and k values.
I just need help.
Your sincerely,,

Equation:
M(t)=Mo - (Mo - Ms)*Pi*8*R*Ms*D [Sum((k*R^2 + Pi^2*D n^2)*k*R^2*t -Pi^2*R^2*D n^2 - (Pi^2*R^2*D n^2*
Exp[-t*(k*R^2 + D*Pi^2 n^2)/R^2])/(k*R^2 + n^2*D*Pi^2)^2]

[Sum] goas from 1 to 1000

Ms=140
Mo=11.58
R=0.004

Variables and Data
t M(t)
0 11.58
30 72.61
60 97.89
90 106.05
120 109.63
150 117.02
180 119.57
210 125.99
240 129.56
270 132.85