Q&A: The Race

We never did resolve the question of which grows faster:

In this corner we have
Sequence 1 n^^n
1, 2^2, 3^3^3, 4^4^4^4, and so on.

And over here we have Sequence 2, defined recursively by

  • The first entry is 1
  • the next entry is 2, followed by one (the previous entry) factorial sign; 2!=2
  • the next entry is 3, followed by two (the previous entry) factorial signs; 3!! = 6! = 720
  • 4, followed by 720 factorial signs, which is a truly staggering number.
  • 5 followed by whatever-the-previous-entry was number of factorial signs, etc.
  • In short, we can define the second sequence as s(1) = 1; s(n) = n, followed by s(n-1) factorial signs.

    Which sequence grows faster than the other??

    We have many conflicting answers, and no decisive resolution; here was one idea .

    Comments (5)

    CF. Mind Boggling!

    Our minds boggle as we continue our quest! This week we discuss the Knuth Arrow notation, for describing some really staggeringly large numbers. And yet we are still two weeks from talking about the largest number ever used for any real purpose!

    We also discuss an April Fool’s paradox! Last week we said there were three errors on the Math Factor. But there were only two, so this announcement was one of the three errors! But then the announcement was correct! ETC.

    Comments

    CE. Big Numbers

    We’re well on our way towards describing the two largest numbers that have ever been used! Unfortunately, there are at least three errors in this segment of the Math Factor–can you spot them all?

    Comments (4)

    Q&A: Why is 0! = 1?

    David R. of Palo Alto writes:

    Have you ever discussed factorials on your podcast? I don’t recall,
    but a friend and I are puzzled and so of course we turn to you: Why
    is “zero factorial” 1? Was it simply defined that way to frustrate
    all of us nonmath folks, or is there a valid explanation?

    Read the rest of this entry »

    Comments

    CD. Alas, Up To A Million Dollars Might Have Been Given Away.

    We discuss the results of the fabulous Math Factor Million Dollar Giveaway. and confess this was an excuse to bring up Game Theory and how to talk about really big numbers.

    Comments (13)

    CC. Fair Division

    The solution to the cake cutting puzzle; the end of the Million Dollar Give-Away.

    Comments

    CB. Pi Day

    We take this week off to celebrate Pi Day (March 1)

    Ok, that’s only π to one decimal place, and only in some countries, but somehow we got off a week in our radio version of the Math Factor and have to catch up.

    Comments (1)

    CA. Cut the Cake!

    How to satisfy the most jealous of triplets?

    Comments

    BZ. Two Teams

    Twenty three people split into two teams of eleven & one ref; no matter how they split, the teams have the same total weight! Can the players themselves be different weights?

    Comments (2)

    BY. Guests at a Party

    A short, but tricky puzzle: how many guests must you invite before you can be sure that there are at least three mutual acquaintances or three mutual strangers?

    Comments (2)

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