Help:=proc(): print(` DiriF(f,s,N), Diri(f,s,N), Conv(f,g,n), MyDiv(n)  `): end:

with(numtheory):

MyDiv:=proc(n) local S,i:

S:={}:

for i from 1 to n do

 if type(n/i,integer) then
   S:=S union {i}:
 fi:

od:

S:

end:


#DiriF(f,s,N):  inputs a discrete function f, and a symbol s and a positive integer N, outputs the first N terms of the Dirichlet series of f(n). Try
#DiriF(n->1,s,10);
DiriF:=proc(f,s,N) local n:
add(f(n)/n^s,n=1..N):
end:


#Diri(f,s,N):  inputs a discrete function f, and a symbol s and a positive integer N, outputs the truncated value at N in floating-point
#Diri(n->1,s,10);
Diri:=proc(f,s,N) local n:
add(evalf(evalc(f(n)/n^s)),n=1..N):
end:


#Conv(f,g,n): the convolution of f(n) and g(n)
Conv:=proc(f,g,n) local S,s:

S:=divisors(n):

add(f(s)*g(n/s),s in S):

end: