[Guest]

Hola! here is a numerical sequence that i just figured out durring 6th period today.

2 - 4 - 6 - 9 - 12 - 16 - ? - ? - ? - ? - ?

try to guess the next 5

[Guest]

  No1slight said:

Hola! here is a numerical sequence that i just figured out durring 6th period today.

2 - 4 - 6 - 9 - 12 - 16 - ? - ? - ? - ? - ?

try to guess the next 5

  Reveal hidden contents

20-25-30-36-42

[Guest]

  No1slight said:

Hola! here is a numerical sequence that i just figured out durring 6th period today.

2 - 4 - 6 - 9 - 12 - 16 - ? - ? - ? - ? - ?

try to guess the next 5

  Reveal hidden contents

20, 25, 30, 36, 42, 49, 56, 64...

3 multiples of 2, the third one is the first of 3 multiples of 3, and it continues like this. This works because the third multiple of any number (like 2) is a multiple of the next number (6=2 times 3)

[Guest]

  ??? said:

  Reveal hidden contents

20, 25, 30, 36, 42, 49, 56, 64...

3 multiples of 2, the third one is the first of 3 multiples of 3, and it continues like this. This works because the third multiple of any number (like 2) is a multiple of the next number (6=2 times 3)

both are right but that's not the rule.

[Guest]

  No1slight said:

both are right but that's not the rule.

  Reveal hidden contents

Add 2 twice consecutively, then add 3 twice consecutively, then add 4 twice consecutively... etc.

[Guest]

Is this the right way to post an answer? just joined, total newbie

2-4-6-9-12-16-20-25-30-36-42-49-56

  No1slight said:

Hola! here is a numerical sequence that i just figured out durring 6th period today.

2 - 4 - 6 - 9 - 12 - 16 - ? - ? - ? - ? - ?

try to guess the next 5

[Guest]

  Phatfingers said:

  Reveal hidden contents

Add 2 twice consecutively, then add 3 twice consecutively, then add 4 twice consecutively... etc.

still, no that isn't it. try to think about powers

"Is this the right way to post an answer? just joined, total newbie

2-4-6-9-12-16-20-25-30-36-42-49-56" - clebr8evrtng

yes that's right no give me the rule and use a spoiler

[Guest]

  No1slight said:

still, no that isn't it. try to think about powers

"Is this the right way to post an answer? just joined, total newbie

2-4-6-9-12-16-20-25-30-36-42-49-56" - clebr8evrtng

yes that's right no give me the rule and use a spoiler

  Reveal hidden contents

For series, "A[1], B[1], A[2], B[2], A[3], B[3], ..."

A[n]=n^2+n

B[n]=(n+1)^2

[tiger_lily111]

I believe the rule is

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Square it & add it.

2, 2^2, 2^2 +2, 3^3, 3^3 +3, 4^4, 4^4 +4, 5^5, 5^5 +5, 6^6, 6^6 +6, 7^7, 7^7 +7

[Guest]

tiger_lily111 and Phatfingers are close but not quite.

keep it up guys and gals!

[Guest]

remember keep thinking powers

and here is a hint. it had to begin with 2 because if i began with 0 or one it wouldn't work.

[Guest]

I have a few ways to get the answer. See if any are the way your looking for.

I'm sure everyone knows the answer is: 20,25,30,36,42. But you want the rule correct?

  Reveal hidden contents

Starting with the 2 you add 2 to get 4, add 2 to get 6, add 3 to get 9, add 3 to get 12, add 4 to get 16, add 4 to get 20, add 5 to get 25, add 5 to get 30, add 6 to get 36, and add 6 to get 42..

If you keep going that way 49, 56, 64 will follow.

  Reveal hidden contents

heres another way of seeing it:

1x2=2

2x2=4

3x2=6

3x3=9

4x3=12

4x4=16

5x4=20

5x5=25

6x5=30

6x6=36

7x6=42

see the pattern there? It works to get 49,56,and 64 and so on.

[spoiler='reason #3

']you said think powers. The only thing I could think up that has to do with powers is:

take the square root of every other number in the sequence and you start to see a pattern. So take 4,9,16,25,36,49,64. If you write it on paper its more clear, but basically it goes 2 to the second power, 3 to the second power, 4 to the second power, 5 to the second power, 6 to the second power and continues on.

Also if you subtract the number by the square root of that number, you get the previous number in the sequence. (for example take 16, subtract it from its square root of 4 and get the 12 in the sequence.)

All three of them methods should continue to follow the same pattern. Idk tho its late. whats up MN!!

[bonanova]

I'd go with James' rule number 2 above as the simplest.

But no rule yet explains the minus signs, unless they were used, instead of commas, for separators.

[Guest]

congratulations James8421!!! you got the answer! yeah i found out how to get from one perfect square to another and decided to make a riddle of it. Good Job guys!!

Edited May 12, 2009 by No1slight

[Guest]

  Reveal hidden contents

so it was 2+ for the first 2 then 3+ for the next two so next 5 are:

20, 25, 30, 36, 42 (i think)

[Guest]

  limitedfund said:

  Reveal hidden contents

so it was 2+ for the first 2 then 3+ for the next two so next 5 are:

20, 25, 30, 36, 42 (i think)

lol not quite right. try to read all the posts (after all this one is only 2 pages long) and you'll find that the answer has been found out by james in his most recent post.

[Guest]

  No1slight said:

lol not quite right. try to read all the posts (after all this one is only 2 pages long) and you'll find that the answer has been found out by james in his most recent post.

i did his first answer was mine

[Guest]

  No1slight said:

lol not quite right. try to read all the posts (after all this one is only 2 pages long) and you'll find that the answer has been found out by james in his most recent post.

Which of James' three answers matched your technique? His third answer seemed to be a pattern of (N^2-N, N^2) where N starts at 2. If N started at 0, that sequence would be:

0, 0, 0, 1, 2, 4, 6, 9, 12, 16, 20, 25, 30, 36, 42, 49, 56, 64, 72, 81, 90, 100 ...

[Guest]

  bonanova said:

I'd go with James' rule number 2 above as the simplest.

But no rule yet explains the minus signs, unless they were used, instead of commas, for separators.

Yes. It helps to flip the first product from "1x2=2" to "2x1=2". Then, you can see a sort of lightning-bolt pattern (down, right, down) to the numbers. Pretty clever technique.

[Guest]

  Phatfingers said:

Yes. It helps to flip the first product from "1x2=2" to "2x1=2". Then, you can see a sort of lightning-bolt pattern (down, right, down) to the numbers. Pretty clever technique.

I found a similar pattern described as: trunc(N*N/4)