- 22

obviously

Nope, a million miles away 

Nope 

I think you'll find 6-28 is -22

QED

496 and 8128

They're perfect numbers.

The numbers which divide into 6 (apart from 6) are 1,2 and 3. 1+2+3=6

28  = 1,2,4,7,14. 1+2+4+7+14=28

496 = 1,2,4,8,16,31,62,124,248  1+2+4+8+16+31+62+124+248=496

8128 = 1,2,4,8,16,32,64,127,254,508,1016,2032,4064  1+2+4+8+16+32+64+127+254+508+1016+2032+4064=8128

*storms off*

Well done El Loro  brilliant 

Then there's amicable numbers, for instance 220 and 284.

The proper divisors of 220 are 1, 2, 4, 5, 10, 11, 20, 22, 44, 55 and 110, of which the sum is 284; and the proper divisors of 284 are 1, 2, 4, 71 and 142, of which the sum is 220.

as soon as I saw numbers I ran - maths is not my strong point 

I have to admit Pengy its not one of my strong points either. I was just watching a  television program where that sequence came up. So I cant claim any credit for it whatsoever 

There aren't many perfect numbers found. Recently they found the 48th perfect number. As it's got 34,850,340 digits in it I won't post it here as I don't have enough time to type it out

Wiki article on perfect numbers:

http://en.wikipedia.org/wiki/List_of_perfect_numbers

Oh bloody bloody bloody shut up

Its  bloody -22

I knew that really.

Me too, I was just giving someone else a chance

Temper temper 

All perfect numbers found so far have been even numbers, but it's never been proved that there aren't any odd numbered perfect numbers.

Ignore 1

The only proper divisor of 3 is 1. Same for 5 and 7.

The proper divisors of 9 are 1 and 3 but that totals 4.

!! and 13 - only 1 is a proper number

15 - proper divisors are 1,3,and 5 totals 9

17 and 19 - only 1 is a proper number

21 - proper divisors are 1,3, and 7 totals 11

23 - only proper divisor is 1

25 - 1 and 5 totals 6

27  - 1, 3 and 9 totals 13

And so on. If you find an odd number whose proper divisors total itself then you will be the first person in the world to do so. Or prove that there are no odd perfect numbers.

El Rolo you have made your point (that you're a ruddy smarty pants)

Now that's enough

PMSL 

Would never have got that, never. 

was that Lewis?

Yep, it was Machel 

Go and sit in the corner and sulk there 

*trudges off with Primary Mathematics Today*

Damn you got there before me El Loro

Hmmm Primary Mathematics Today states the vast majority of mathematical knowledge is possessed to massage the ego and is of no real use in an every day setting.

It also says the answer is -22

Yes, but -22 is the answer to a sum. The question that was posed here was not a sum.

If you check 'Primary Mathematics Today' has an asterisk against '-22'

 and the asterisk says 'This is only the answer if the original question was a sum.'

Erm .. the sequence given IS a sum

Hence the next 2 number are the ANSWER

I still don't know what a perfect number is.  Is it a number that always did what it was told, kept its room tidy, ate its greens and always did its homework?

In number theory, a perfect number is a positive integer that is equal to the sum of its proper positive divisors, that is, the sum of its positive divisors excluding the number itself (also known as its aliquot sum). Equivalently, a perfect number is a number that is half the sum of all of its positive divisors (including itself) i.e.σ₁(n) = 2n.

Well you did ask Kaffy 

I still don't know what a perfect number is.

By the way - does anyone know what language moonie speaks?

Moonie speaks "I aint had a shag in ages" so I chat mathematics