Partition of a number with no 1s

Hi.

I have problems solving this problem:

How many partitions of a number n are there, if none of the components of the partition equals 1?

What I've got so far is that for
n=1 we have 0,
n=2 and n=3 we have 1
n=4 and n=5 we have 2
n=6 and n=7 we have 3

but then for n=8 we get 7 and for n=9 we get 8.

Unless I'm making mistakes while counting. Anyway, I do not see any relations here.

Could someone help me?

Quote:

---

Originally Posted by wilhelm

How many partitions of a number n are there, if none of the components of the partition equals 1?
What I've got so far is that for
n=1 we have 0,
n=2 and n=3 we have 1
n=4 and n=5 we have 2
n=6 and n=7 we have 3
but then for n=8 we get 7 and for n=9 we get 8.
Unless I'm making mistakes while counting. Anyway, I do not see any relations here.

---

This is a rather deep question.
If you look at this webpage, you will see how deep.

The function you want is . But there is no easy way to define that function.

I'm sorry, I don't see that; describes the number of n using 2 numbers, right? But in the problem above

but not

but not for example

That's why I don't understand why we should consider the function

Quote:

---

Originally Posted by wilhelm

I'm sorry, I don't see that; describes the number of n using 2 numbers, right? But in the problem above

---

Here is the quote:
For any given value of k, partitions counted by p(k, n) fit into exactly one of the following categories:
smallest addend is k
smallest addend is strictly greater than k.