5th puzzle post-the impossible sequence

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Discussion Overview

The discussion revolves around a numerical puzzle involving a sequence of numbers: 9, 36, 225, 256, 400, _, 1225, 1600. Participants explore potential patterns and methods to identify the missing number in the sequence, with varying approaches and interpretations of the underlying logic.

Discussion Character

  • Exploratory
  • Mathematical reasoning
  • Debate/contested

Main Points Raised

  • One participant suggests a pattern involving multiplying a sequence of numbers (3, 3, 5, 4, 4, 6, 5, 5, 7) with another sequence (1, 2, 3, 4, 5, 6, 7, 8) and squaring the results, leading to the conclusion that the missing number is 1296.
  • Another participant questions the origins of the numbers in the sequence and expresses uncertainty about the significance of the pattern proposed by the first participant.
  • A different approach is introduced, where a participant claims that the numbers represent the count of letters in the English words for the numbers 1 to 8, suggesting that the missing number could be 324.
  • Further mathematical expressions are provided by a participant, detailing a formula that generates the sequence but does not clarify the relationship to the original puzzle.

Areas of Agreement / Disagreement

Participants do not reach a consensus on the correct approach or the missing number, with multiple competing views and methods presented throughout the discussion.

Contextual Notes

There are unresolved assumptions regarding the significance of the patterns and the definitions of the sequences being discussed. The mathematical steps leading to the proposed solutions are not fully clarified, leaving some ambiguity in the reasoning.

michealsmith
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:cool:


o.k wats missing from the LINE UP...

9,36,225,256,400, _ ,1225,1600 .

damm, u got all the others instantly.. hope it isn't the case for this ...its a 3 step solution ...sorta ,nothing too ridiculous ,,and its slightly lateral and mensa ' ry.
goood luck
btw who ever solves it post as clearer method as possible
 
Last edited:
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Well, I found a pattern, though if this is the one you’re looking for is anyone’s guess.
Take the pattern, 3, 3, 5, 4, 4, 6, 5, 5, 7,…..
Multiply it term by term with the pattern 1, 2, 3, 4, 5, 6, 7, 8
Square each one, then the pattern is
(3x1)^2 = 9
(3x2)^2 = 36
(5x3)^2 = 225
(4x4)^2 = 256
(4x5)^2 = 400
(6x6)^2 = 1296
(5x7)^2 = 1225
(5x8)^2 = 1600
So the answer is 1296
 
yep dav yep but wat r the origins of those numbers on the left ...the ones on the far left...
btw how do u make ur writting invisible i don't know how to do that
 
Last edited:
michealsmith said:
yep dav yep but wat r the origins of those numbers on the left ...the ones on the far left...
btw how do u make ur writting invisible i don't know how to do that

I'm not sure if you're looking for something else that's significant about the series 3,3,5,4,4,6,5,5,7,6,6,8,7,7,9... But essentially daveb's answer was:

F1(n) = F1(n-1)+1*(n%3)*((n-1)%3)-.5*((n-1)%3)*((n-2)%3)
F1(0) = 3

(A complicated way of getting +0, +2, -1, +0, +2, -1, +0, +2, -1, etc.)

F(n) = ((F1(n-1)+1*(n%3)*((n-1)%3)-.5*((n-1)%3)*((n-2)%3)) * (n+1))^2

As for the invisible writing, it's pretty simple-- You enter:

Now you see me

Which becomes:

Now you don't!

DaveE
 
Last edited:
acttually i was just going for the fact that each number represeted the amount of letters in the numbers from ...1 to 8 ...which makes it (3x6)^2 = 324
 

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