SOLUTION: Some prime numbers are of the form {{{2^n-1}}}. For example, the prime number 7 is equal to {{{2^3-1}}}. Make a list of the first seven exponents (n<20) that produce prime numbers

Algebra ->  Finance -> SOLUTION: Some prime numbers are of the form {{{2^n-1}}}. For example, the prime number 7 is equal to {{{2^3-1}}}. Make a list of the first seven exponents (n<20) that produce prime numbers       Log On


   



Question 1209417: Some prime numbers are of the form 2%5En-1. For example, the prime number 7 is equal to 2%5E3-1. Make a list of the first seven exponents (n<20) that produce prime numbers of this type (include the number 3 as one of the seven in your list).
CC11F #5

Answer by ikleyn(52781) About Me  (Show Source):
You can put this solution on YOUR website!
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Some prime numbers are of the form 2%5En-1. For example, the prime number 7 is equal to 2%5E3-1.
Make a list of the first seven exponents (n<20) that produce prime numbers of this type
(include the number 3 as one of the seven in your list).
CC11F #5
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ANSWER. The first seven exponents n < 20 that produce prime numbers of the form 2%5En-1 are 2, 3, 5, 7, 13, 17, and 19.

For the solution, see the link

https://www.google.com/search?q=.+Some+prime+numbers+are+of+the+form+%7B%7B%7B2%5En-1%7D%7D%7D.+For+example%2C+the+prime+number+7+is+equal+to+%7B%7B%7B2%5E3-1%7D%7D%7D.+Make+a+list+of+the+first+seven+exponents+(n%3C20)+that+produce+prime+numbers+of+this+type+(include+the+number+3+as+one+of+the+seven+in+your+list).+CC11F+%235&rlz=1C1CHBF_enUS1071US1071&oq=.+Some+prime+numbers+are+of+the+form+%7B%7B%7B2%5En-1%7D%7D%7D.+For+example%2C+the+prime+number+7+is+equal+to+%7B%7B%7B2%5E3-1%7D%7D%7D.++Make+a+list+of+the+first+seven+exponents+(n%3C20)+that+produce+prime+numbers+of+this+type++(include+the+number+3+as+one+of+the+seven+in+your+list).+CC11F+%235&gs_lcrp=EgZjaHJvbWUyBggAEEUYOdIBCTQwNjdqMGoxNagCCLACAQ&sourceid=chrome&ie=UTF-8

This solution is provided by artificial intelligence (AI) by my request.


Among the obvious facts that are useful to know,  in order for  2%5En-1  be
a prime integer number,  the exponents n must be an odd integer number.

The even exponents n, higher than 2, produce composite numbers.


Among other useful facts to know is THIS:

        if the exponent n is a composite number,
        then  2%5En-1  is a composite number,  too.

So,  for such a search as in this problem,  you should look among prime exponents n,
rejecting composite exponents n.


Enjoy (!)