Here c = the empirical 0.98 quantile for the sum of n Paretos:

And we're doing 10 million simulations of each sum.
Really 10 million; i.e. when n=5, we're actually 
generating 50 million Paretos altogether, 5 for each sum.


n =  2  a =  0.5  c =  10000.17 
n =  2  a =  0.6666667  c =  1012.340 
n =  2  a =  1  c =  104.7153 
n =  2  a =  1.5  c =  24.01130 
n =  5  a =  0.5  c =  62436.65 
n =  5  a =  0.6666667  c =  4029.958 
n =  5  a =  1  c =  271.3259 
n =  5  a =  1.5  c =  50.38605 
n =  10  a =  0.5  c =  249338.2 
n =  10  a =  0.6666667  c =  11406.04 
n =  10  a =  1  c =  555.4726 
n =  10  a =  1.5  c =  88.03292 
n =  20  a =  0.5  c =  1004949 
n =  20  a =  0.6666667  c =  32489.57 
n =  20  a =  1  c =  1127.164 
n =  20  a =  1.5  c =  153.8022 
n =  50  a =  0.5  c =  6237558 
n =  50  a =  0.6666667  c =  128040.7 
n =  50  a =  1  c =  2888.229 
n =  50  a =  1.5  c =  326.4243 
n =  100  a =  0.5  c =  25040967 
n =  100  a =  0.6666667  c =  363796.4 
n =  100  a =  1  c =  5851.764 
n =  100  a =  1.5  c =  583.2789