prime numbers funny

I took the prime numbers from this link:
http://nl.wikibooks.org/wiki/Wiskunde/Getallen/Lijst_priemgetallen
I did take the first three lines
I did the following with the numbers
The prime 11 = 1+1 = 2
The prime 13 = 1+3 = 4
The prime 17 = 1+7 = 8 and so on
This is the result for the three rows"
2 3 5 7 2 4 8 1 5 2 4 1 5 7 2 8 5 7 4 8 1 7 2 8 7 2 4 8 1 5 1 5 2 4 5 7 4 1 5 2 8 1 2 4 8
1 4 7 2 4 8 5 7 8 5 2 8 1 7 2 4 5 1 5 7 2 7 4 5 7 2 8 7 4 1 5 2 1 5 4 5 7 8 1 7 2 8 7 2 4
8 2 1 5 4 8 5 8 1 1 7 8 5 2 4 1 2 8 5 7 4 1 5 7 1 2 4 8 5 2 4 7 2 8 7 8 7 8 7 4 1 5 4 1 5
There is only once the number 3 and never again does it come up
( I did the same for larger primes)
The numbers 3 6 9 never show when I use this method
The numbers 124578 only show, Funny is
1+2=3 4+5=9 7+8=15=1+5=6 (396) (124578)
Can you please explain this?
Kind regards Rene

When the digits of a number is added up,

If the sum is divisible by 3 - the number is divisible by 3.

So if 3 or 6 or 9 turned up for any number in the sequence - that number would be divisible by 3 and not a prime number (other than 3 itself - which is a prime number).

That is why 3, 6 or 9 does not show up in your sequence!!

Subhotosh Khan said:

When the digits of a number is added up,

If the sum is divisible by 3 - the number is divisible by 3.

So if 3 or 6 or 9 turned up for any number in the sequence - that number would be divisible by 3 and not a prime number (other than 3 itself - which is a prime number).

That is why 3, 6 or 9 does not show up in your sequence!!

Click to expand...

Yes, I understand, stupid! Thanks.

Teragabaga said:

Yes, I understand, stupid! Thanks.

Click to expand...

Hi all.
But what me makes wonder is, the numbers 3 6 9 do not appear for Obvious reasons.
Only the numbers (124578) But these numbers make up the "missing" numbers 3-6-9?
1+2=3 4+5=9 7+8=15=1+5=6 (396)(124578)
Why is this so?
Thanks, Rene

Teragabaga said:

Hi all.
But what me makes wonder is, the numbers 3 6 9 do not appear for Obvious reasons.
Only the numbers (124578) But these numbers make up the "missing" numbers 3-6-9?
1+2=3 4+5=9 7+8=15=1+5=6 (396)(124578)
Why is this so?
Thanks, Rene

Click to expand...

That really does not need a reason. You can add-subtract-multiply those numbers to came with all kinds of numbers.

If you make 9 digit numbers - using 1 - 9 only once, you'll have numbers divisible by 3.

124578 is divisible by 3 - in any order. So by adding different digits - you can come with different numbers that are divisible by 3 - and reduces to 3 or 6 or 9 upon adding the digits.

If you add digits in 124578 - by skipping every other digits → you'll get 1+4+7 = 12 → 3 and 2+5+8 = 15 → 6 again those properties of numbers divisible by 3.