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How to eliminate duplicates in a list preserving previous order Ex: if A=[1,5,3,3,4,9,9,9,1] I want to obtain [1,5,3,4,

How to eliminate duplicates in a list preserving previous order Ex: if A=[1,5,3,3,4,9,9,9,1] I want to obtain [1,5,3,4,

How to eliminate duplicates in a list preserving previous order Ex: if A=[1,5,3,3,4,,9,9,9,1] I want to obtain [1,5,3,4

How to eliminate duplicates in a list preserving previous order Ex: if A=[1,5,3,3,4,,9,9,9,1] I want to obtain [1,5,3,4

How to eliminate duplicates in a list preserving previous order Ex: if A=[1,5,3,3,4,,9,9,9,1] I want to obtain [1,5,3,4

Is there any extrapolation method already implemented in Sage? Something like Aitken extrapolation, or Richardson extrap

Thank you!

Wow! Thank you

I tried this

%timeit

pp=previous_prime;

w=[n for n in prime_range(5,1000) for m in prime_range(n//2,n) for k in prime_range(m//2,m) if m==pp(n) and k==pp(m) and (n+m+k).is_prime()];

(5 loops, best of 3: 861 ms per loop)

It works, but it is way slower than the original here:

%timeit

pp=previous_prime;

w=[n for n in prime_range(5,1000) if (n+pp(n)+pp(pp(n))).is_prime()];

(125 loops, best of 3: 1.61 ms per loop)

For example in place of

pp=previous_prime;

w=[n for n in prime_range(5,100) if (n+pp(n)+pp(pp(n))).is_prime()];

I wold like to write something like this:

w=[n for n in prime_range(5,100) if (n+m+k).is_prime() "where" m=pp(n) and k=pp(m)];

Is that possible in some way?

Can one create a list with some assumptions inside [ ], without having to make loops?

I would like to create a list with one or more assumptions, without making loops.

I mean that (1275,1309) is a solution for the same problem (with same notations as in my answer) with R=[(-1,-1),(-1,0),(-1,1),(0,-1),(0,0),(0,1),(1,-1),(1,0),(1,1)]

I mean, if we consider this example, when the flag goes to zero, I would go directly to next n, without the program having to try all other p,q,r, something like the od "goto":

N=100; v=[]   #  v = [n that cannot be written as p*q+q*r+r*p with p,q,r prime]
for n in prime_range(1,N):
    flag=True
    for p in prime_range(2,N):
        for q in prime_range(p,N):
            for r in prime_range(q,N):
                if flag and n==p*q+q*r+r*p:
                    flag=False; print n,p,q,r;  break
   if flag: v.append(n)
print v

How would you write such a program (possibly also with rising exception, which I don't know)?