(

readbaby2000@... does not exist)

The address for the group is:

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You should use this address to post a new thread.

To comment and reply to an existing thread, hit 'Reply to All'. This ensures

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original sender.

>c=0;for (n=1,1000,if (sigma

(n,0)%2==0,c++);print(c)

is Pari/GP code. Pari/GP is an excellent and powerful calculator, avaiable

for free from:

http://www.gn-50uma.de/ftp/pari/00index.html
tau(n) is the count of the number of divisors of n.

If n=p1^e1..pk^ek,

then tau(n)=(e1+1)...(ek+1)

e.g. 12=2^2.3, tau(12)=(2+1)(1+1)=6

which means that 12 has 6 divisors, namely 1,2,3,4,6 and 12.

iff tau(n) is even

means that if tau(n) is even then the door is closed, else the door is open

(iff means if and only if).

Hope this helps.

Jon Perry

perry@...
http://www.users.globalnet.co.uk/~perry/maths
BrainBench MVP for HTML and JavaScript

http://www.brainbench.com
-----Original Message-----

From: readbaby2000 [mailto:

readbaby2000@...]

Sent: 29 July 2002 18:21

To: Jon Perry

Subject: Re: a really cool problem to solve that will teach alot about

primes

hi, i wanted to know how to post messeges to the group. when i posted

the problem with the lockers, i meant it to be for the whole group.

only you got the messege. how do i post?

also, i think you solved the problem but i cant tell because of the

language you used. what in the world does "iff tau" mean? and sigma,

tau(n) in fact i dont get this whole line:(c=0;for (n=1,1000,if (sigma

(n,0)%2==0,c++);print(c))

i think you got it though. but can u please explain it in english?

thanx

Jon Perry

perry@...
http://www.users.globalnet.co.uk/~perry/maths
BrainBench MVP for HTML and JavaScript

http://www.brainbench.com
-----Original Message-----

From: readbaby2000 [mailto:

readbaby2000@...]

Sent: 29 July 2002 18:21

To: Jon Perry

Subject: Re: a really cool problem to solve that will teach alot about

primes

hi, i wanted to know how to post messeges to the group. when i posted

the problem with the lockers, i meant it to be for the whole group.

only you got the messege. how do i post?

also, i think you solved the problem but i cant tell because of the

language you used. what in the world does "iff tau" mean? and sigma,

tau(n) in fact i dont get this whole line:(c=0;for (n=1,1000,if (sigma

(n,0)%2==0,c++);print(c))

i think you got it though. but can u please explain it in english?

thanx