April 2, 2007
·
answers, numbers, Q&A
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 .
Permalink
April 1, 2007
·
numbers, paradoxes, The Mathcast
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.
Permalink
March 24, 2007
·
errata, math puzzles, numbers, The Mathcast
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?
Permalink
March 20, 2007
·
numbers, Q&A
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 »
Permalink
March 19, 2007
·
Favorites, game theory, math puzzles, Mathfactor Events, numbers, The Mathcast
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.
Permalink
March 15, 2007
·
answers, The Mathcast
The solution to the cake cutting puzzle; the end of the Million Dollar Give-Away.
Permalink
March 7, 2007
·
Mathfactor Events, The Mathcast
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.
Permalink
February 28, 2007
·
math puzzles, The Mathcast
How to satisfy the most jealous of triplets?
Permalink
February 21, 2007
·
math puzzles, The Mathcast
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?
Permalink
February 12, 2007
·
math puzzles, The Mathcast
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?
Permalink