Question 1062750: Write a program to print the following series
2 5 11 17 23 31 41 47 59 ...
Found 2 solutions by rothauserc, Edwin McCravy:
Answer by rothauserc(4718)   (Show Source):
You can put this solution on YOUR website! This is a list of every second prime beginning with 2.
:
The index into the list of primes would be (2n-1) where n = 1, 2, ......k
:
You would have to set k to some integer, for example 100
:
There are plenty of examples of c or java code on the internet to generate prime numbers, store them in a matrix and then use the index (2n-1) into the matrix to print out the every second prime number list
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Answer by Edwin McCravy(20064)  (Show Source):
You can put this solution on YOUR website!
The sequence is the 1st prime, the 3rd prime, the 5th prime, etc., i.e.
every other prime.
The only language I know is LibertyBasic. Here is the program in that
language. The ' indicates a comment line.
--------------------------------------------------------------------------
'We begin by printing the first term. The only term that's even.
'and setting the prime count = 1
print 2;" ";
count = 1
'Now we need try only odd numbers n from 5 to 100. That's why the
'step 2" in the next executable line. If we want numbers higher
'than 100, then we change the 100 to a higher number.
for n = 3 to 100 step 2
pr = 1
'We test each n to see if it is prime. We use 1 or 0
'values of "pr" to indicate whether n is prime or not
'if pr=1 it is prime, and if pr=0 it is not prime
'We started above by setting pr=1, for we change pr to 0
'if n is not prime. Since n is odd, we only
'need to see if n is divisible by odd numbers,
'which is why the "step 2" in the next line.
for k = 3 to n-1 step 2
'the next line makes pr=0 if n is divisible by k
if n mod k = 0 then pr=0
next k
'if n is not prime the next line skips to 1 for the next n value
if pr = 0 then 1
'if n is prime, we increase the prime count by 1
count = count+1
'the next line determines whether the count is even or
'odd. If it's odd, we print n; if even we skip to 1
if count mod 2 = 0 then 1
print n;" ";
1 next n
print "..."
-----------------------------------------
Edwin
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