a "primorial" limit

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  • Опубліковано 18 лис 2024

КОМЕНТАРІ • 41

  • @emanuellandeholm5657
    @emanuellandeholm5657 4 місяці тому +26

    Numerically, I get something slowly creeping towards "e".

  • @adrianamor8472
    @adrianamor8472 4 місяці тому +7

    The fact that this limit is finite, swapping n# for n! turns into an infinite limit and that the number of primes is infinite. Shocking

  • @BadlyOrganisedGenius
    @BadlyOrganisedGenius 4 місяці тому +33

    This implies the primorials have something akin to Stirling's approximation:
    nth_root(n#) ~ e as n -> ∞
    so n# is roughly approximated by e^n
    crazy

    • @sleepycritical6950
      @sleepycritical6950 4 місяці тому +5

      Yes but it’s not a very good approximation unlike the Stirling approximation.

  • @TedHopp
    @TedHopp 4 місяці тому +19

    Just one little bit to pick: Abel summation is named for Neils Henrik Abel, a Norwegian, whose last name is pronounced AH-bel, not like the English word "able."

  • @kashiark
    @kashiark 20 днів тому

    You can write f(x) as an infinite sum with Heaviside functions, and then integrate by parts normally recognizing that the derivative of the Heaviside function is the delta function.

  • @goodplacetostop2973
    @goodplacetostop2973 4 місяці тому +38

    11:46 Yikes

    • @benardolivier6624
      @benardolivier6624 4 місяці тому +12

      At least it was a good place... 😉

    • @Alan-zf2tt
      @Alan-zf2tt 4 місяці тому +2

      ... and it is an excellent place to start

  • @msdmathssousdopamine8630
    @msdmathssousdopamine8630 4 місяці тому +2

    What a cute limit. Love it ! 👍❤

  • @vasilisr7
    @vasilisr7 4 місяці тому +2

    That's some interesting math

  • @PotatoImaginator
    @PotatoImaginator 4 місяці тому +3

    How does he always know the good place to stop? 😮

  • @fortetwomusic
    @fortetwomusic 4 місяці тому

    That's a good place indeed.

  • @paolonicolacerea
    @paolonicolacerea 4 місяці тому +3

    I weigh seven/eight/nine/ten pound! 😂

  • @MrGyulaBacsi
    @MrGyulaBacsi 4 місяці тому

    amazing derivation!

  • @themptytree3145
    @themptytree3145 4 місяці тому +1

    Do it instantly with Cauchy-d'Alembert

  • @Axacqk
    @Axacqk 4 місяці тому

    I think it's more like an alternative statement of the prime number theorem.

  • @sniffbird
    @sniffbird 4 місяці тому +1

    What a COOL RESULT !!!!!

  • @mskellyrlv
    @mskellyrlv 4 місяці тому

    That's impressive!

  • @charlievane
    @charlievane 4 місяці тому

    Thanks

  • @Alan-zf2tt
    @Alan-zf2tt 4 місяці тому

    I wish I could understand all this stuff as a type of muscle memory.
    But when I try to take it in by one ear - just like Homer Simpson - some of the old stuff drops out the oither ear - : shrug :

  • @59de44955ebd
    @59de44955ebd 4 місяці тому

    Fun fact: the limit of 1/n * (n!)^(1/n) is instead 1/e, so by replacing the primorial with the factorial and then dividing the result by n we get the exact reciprocal as limit. Not sure what that means though ;-)

    • @59de44955ebd
      @59de44955ebd 4 місяці тому +2

      But whatever it means, we can combine both limits to find another one: If we define n? as the "anti-primorial", i.e. the product of all natural numbers 1/(e^2)

  • @cicik57
    @cicik57 4 місяці тому

    need explanation about PNT and the homework :D

  • @hqTheToaster
    @hqTheToaster 4 місяці тому +1

    Interesting.

  • @alexandrepereira3902
    @alexandrepereira3902 4 місяці тому +1

    I guess for n! the solution will follow a similar path… or not?

    • @bjornfeuerbacher5514
      @bjornfeuerbacher5514 4 місяці тому +2

      Michael did already several videos using different methods for n!, if I remember correctly.

  • @cycklist
    @cycklist 4 місяці тому +7

    This is a pound symbol: £

    • @BridgeBum
      @BridgeBum 4 місяці тому

      That is the monetary pound. # is the weight pound symbol.

    • @charlievane
      @charlievane 4 місяці тому

      we may be living in a post-hashtag world

  • @xinpingdonohoe3978
    @xinpingdonohoe3978 4 місяці тому

    I would have just said n primorial. All these pounds make it sound like a money problem, or even a mass problem.

  • @adityaekbote8498
    @adityaekbote8498 4 місяці тому

    Noice

  • @alexandrepereira3902
    @alexandrepereira3902 4 місяці тому

    Supercool… as always

  • @f5673-t1h
    @f5673-t1h 4 місяці тому +2

    Guess before finishing the video: The answer is 1.
    Primes get sparser indefinitely.

    • @015Fede
      @015Fede 4 місяці тому +1

      Well. Your wrong

    • @robertveith6383
      @robertveith6383 4 місяці тому +3

      ​@@015Fede -- Well, you're wrong, when you misspelled "you're."

  • @CTJ2619
    @CTJ2619 4 місяці тому +1

    en.wikipedia.org/wiki/Primorial_prime#:~:text=In%20mathematics%2C%20a%20primorial%20prime,sequence%20A057704%20in%20the%20OEIS).

    • @Alan-zf2tt
      @Alan-zf2tt 4 місяці тому +1

      Did you mean https ://en .wikipedia .org /wiki / Primorial_prime# |?|