Math · 3
Fermat wrongly claimed his formula 2^(2^n)+1 always produced primes—what is the numerical value of the fifth term, which turned out to be composite?
Answer
4,294,967,297
The fifth Fermat number, 2^32+1, equals 4,294,967,297 and is composite, disproving Fermat's conjecture that all numbers of this form are prime.
💡 Did you know?
Pierre de Fermat believed every number of the form 2^(2^n)+1 was prime. He was right for n=0,1,2,3,4 but catastrophically wrong—the fifth one factors into 641×6,700,417.
Other options people guess
- 4,294,967,296
- 2,147,483,647
- 8,589,934,593
Topics
- fermat-numbers
- prime-numbers
- history-of-math
- number-theory
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