This block finds the nth-primenumber
I hope that it is usefull for anyone.
primo(n):=block(
if n=1 then return(2) else(p:1,
k:1),
while k#n do
(p:p+2,
d:2,
while (d*d<=p and mod(p ,d)#0) do
(d:d+1),
if d*d>p then k:k+1),
return(p))$
Example (15th prime):
primo(15);
47
makelist(primo(i),i,1,55);
[2,3,5,7,11,13,17,19,23,29,31,37,41,43,47,53,59,61,67,71,73,79,83,89,97,101,
103,107,109,113,127,131,137,139,149,151,157,163,167,173,179,181,191,193,197,199,211,223
,227,229,233,239,241,251,257]
Best
Luigi Marino