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Sequence problem.

I'd appreciate help with the following problem:

What is the next number in the following sequence?

100, 196, 484, 676, ?

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Reply 1

Mr M

Study Forum Helper

Would it help to know that the term before 100 could be 36 and the one before that could be 16. Do you recognise those numbers?

Reply 2

Mr M

Study Forum Helper

Have you missed out 324 as a term by the way? If you haven't my advice stands. If you have the previous terms would be 4 and 36.

Reply 3

Chucklefiend

Original post by Mr M

Have you missed out 324 as a term by the way? If you haven't my advice stands. If you have the previous terms would be 4 and 36.

No, I have copied the sequence as it appears. I'm not sure I'm following your clues. However, I think I've found a method that works. It looks like the happy prime sequence +3 then squared. So the next number in the sequence would be 1020, is this what you made it?

(edited 13 years ago)

Reply 4

Mr M

Study Forum Helper

Original post by Chucklefiend

No, I have copied the sequence as it appears. I'm not sure I'm following your clues. However, I think I've found a method that works. It looks like the happy prime sequence +3 then squared.

They don't need to be happy primes to generate that sequence but squaring primes is involved.

Reply 5

Mr M

Study Forum Helper

Original post by Chucklefiend

So the next number in the sequence would be 1020, is this what you made it?

I got 1156 and so does Sloane. That doesn't mean your sequence isn't valid. Gimme a second to check.

Edit: Actually I don't need to check as 1020 isn't square!!

(edited 13 years ago)

Reply 6

ghostwalker

Original post by Chucklefiend

However, I think I've found a method that works. It looks like the happy prime sequence +3 then squared.

196 = 14^2 = (11+3)^2 and 11 is not happy. :sad:

Reply 7

Chucklefiend

Original post by ghostwalker

196 = 14^2 = (11+3)^2 and 11 is not happy. :sad:

doh!

Reply 8

Mr M

Study Forum Helper

Original post by Chucklefiend

doh!

Just make a list of all the squares of the primes and take it from there.

Reply 9

Dragon

The sequence is

10^2

14^2

22^2

26^2

. Not sure what that tells you...

Reply 10

BJack

Original post by Dragon

The sequence is

10^2

14^2

22^2

26^2

. Not sure what that tells you...

Not even with Mr M's last hint?

Reply 11

Mr M

Study Forum Helper

Original post by Dragon

The sequence is

10^2

14^2

22^2

26^2

. Not sure what that tells you...

Write down a list of primes.

Write down 10, 14, 22, 26 underneath.

Try to line the lists up in a way that makes sense.

Reply 12

Chucklefiend

Original post by Dragon

The sequence is

10^2

14^2

22^2

26^2

. Not sure what that tells you...

Well I can see why Mr M thought there was a value missing.

Reply 13

boromir9111

Original post by Dragon

The sequence is

10^2

14^2

22^2

26^2

. Not sure what that tells you...

It tells you the square numbers are having a party here

Reply 14

Mr M

Study Forum Helper

Original post by boromir9111

It tells you the square numbers are having a party here

A square dance?

Reply 15

boromir9111

Original post by Mr M

A square dance?

darn it, you always come out with the good ones :tongue:

Reply 16

blue_shift86

Original post by Chucklefiend

I'd appreciate help with the following problem:

What is the next number in the following sequence?

100, 196, 484, 676, ?

it's 10^2 14^2 22^2 26^2

i think sequence is missing 18^2 though

edit, this could be one of many sequences cos there aren't enough terms. I mean u could have gap of (+8)^2 after the 4th term or you could have (+4) ^ 2 etc