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Sun 28 Mar, 2004 05:54 am
A list of sequences are going around at college. Perhaps you can solve some and give an explaination how the logic works.
Whim
Whim,
Do the question marks in the above all represent numbers or could some be mathematical symbols?
I think all numbers or (letters if appropriate), but you're never sure with these type of puzzles. If you have a logical explanation, you have to decide yourself if you do not think it's to far fetched. The simplest method is mostly best.
Whim.
The only thing I can see thats significant about No. 1 is that each no. is 99099 larger than the one before it.
1126311 +99099 = 1225410 + 99099 =1324509 +99099 =1423608 + 99099 = 1522707
I feel I should now have seen this but I'm getting blanker by the minute
I think you have it Kev.
+99099 +99099 +0 +99099 +99099 + 0 +99099 +99099 +0 etc.
1126311, 1225410, 1225410, 1324509, 1423608, 1423608, 1522707
whim
If the middle ? in question no.9 stood for "therefore" it would be:
1+4=5+4=9+4=13+4=17+4=21 (therefore) 19-4=15-4=11-4=7-4=3
# 2 is a "fibonacci sequence", but you need more than 3 blanks to reach 65. Numbers are the sum of the two preceding numbers
2, 3, 5, 8, 13, 21, 34, 65
Equus 21+34 =55 not 65 unless Whim has a typo
My guess is 24 in the middle..
1, 5, 9, 13, 17, 21, 24, 19, 15, 11, 7, 3
+4 -4. Leaves a problem in the middle.
21+4 = 25
............24 in between
19+4 = 23
Whim
No typo here. I copied directly from the list. It looks like fibonacci, but I guess that's the trick. Or the list has a typo.
It's just a guess of mine kev. I'm not happy with it.
21+ 4 = 25 23-4=19
The middle number should be 25 or 23
And I met the number half way (24)
Whim
Re: hard sequences
whimsical wrote:A list of sequences are going around at college. Perhaps you can solve some and give an explaination how the logic works.
3. 3, 0, 1, 5, 1, 5, 7, 2, 49, ?, ?, ? 9, 3, 729
Whim
I think the clue here is:
7,2,49,and
9,3,729,
7,2,49, x^2
9,3,729 x^3 (sorry I dont know how to lay it out)
This is not a coincidence is it?
Kev, Please understand I was always bad at math. I thought I was onto something. Sorry.
(There are three types of people in the world, those that are good at math, and those that aren't)
Equus I posted the same thing that you did yesterday it was about an hour later when I realised my mistake, and deleted it.
So we both fell into the same trap, I'm no good at math either.
2. times two minus one 2,3,5,9,17,33,65
I agree with
3. 3^0=1 5^1=5 7^2=49 9^3=729
Numbers go
a1 b1 a1^b1 a2 b2 a2^b2
Where a1=3, a2=5, an= 2*n+1
b1=0,b2=1,b3=2 .. bn =n-1
5. Is simple :
*edited first sequence
4 5 6 7 8 ; 18 19 20 21 22 ; 60 61 62 63 64 ; 186 187 188 189 190 ; 564 564 566 567 568
First in next quintet is first in previous quintet times 3 plus 6 (or middle in prev. quintet times 3). Then quintet is progressive step 1.
9. Works in 'spiral'
List all even numbers from 1 to 21,
starting from left , then right, then left, going inward
1
1 3
1 5 3
1 5 7 3
etc... to obtain
1 5 9 13 17 21 23 19 15 11 7 3
Number 8:
8: 0, 111, 12123311 , 123121345531311 , 123412312145677531531311
The logic?
Well, let's split up 123412312145677531531311:
1234
123
12
1
4567
7531
531
31
1
It begins by 1234, the progressive sequence (A) from 1->N. (N=4 in this case). All sequences that can be obtained by removing last number are listed (down to 1). Then the N->2N-1 sequence follows in the middle (B), then 2N-1 -> 1 sequence (C) which is descending on odd numbers, removing the first in sequence and repeating.
For n=1 we have
1 (sequence A)
1 (sequence B)
1 (sequence C)
for n=2
12 (sequence A)
1
23 (sequence B)
31 (sequence C)
1
for n=3
123 (sequence A)
12
1
345 (sequence B)
531 (sequence C)
31
1