Hi Sandhya Pai,
As per my understanding you want to write the zeroth and the first order modified bessels function of second kind. I have written my code below. I hope you find it useful.
gam=0.5772156649;
x = 5;
I0 = 1;
for k1 = 1:10
I0 = I0 + (((x.^2)./4).^k1)/(factorial(k1)^2);
end
I0m = besseli(0,x);
I0cmp = [I0m I0]
K0 = -(log(x/2)+gam)*I0;
frx = 0;
for k1 = 1:10
frx = frx + 1/k1;
K0 = K0 + (frx*(((x.^2)./4).^k1)/(factorial(k1)^2));
end
K0m = besselk(0,x);
K0cmp = [K0m K0]
NOTE: My notation corresponds to that in Abramowitz and Stegun, except for using x where they use z
