What's the next number in this sequence

[deftron]

1 ... 4 ... 7 ... 11 ... 15 ... 18 ... 21 ... 24 ... 27 ...



What's the next number in the sequence?
Please explain why , too.

 

[dug777]

777

 

[bandana163]

31

1 - 4 - 7
11 - 15 - 18
(2)1 - (2)4 - (2)7
(3)1 - (3)5 - (3)8

Probably.

 

[ribbon13]

Originally posted by: Vaerilis
31

1 - 4 - 7
11 - 15 - 18
(2)1 - (2)4 - (2)7
(3)1 - (3)5 - (3)8

Probably.

Damn quick.

 

[deftron]

Originally posted by: Vaerilis
31

1 - 4 - 7
11 - 15 - 18
(2)1 - (2)4 - (2)7
(3)1 - (3)5 - (3)8

Probably.

Nope

 

[bandana163]

My next guesses would be: 4; 22; 41; 1111.

 

[SithSolo1]

32

 

[deftron]

Originally posted by: Vaerilis
My next guesses would be: 4; 22; 41; 1111.

None of those

 

[deftron]

Originally posted by: SithSolo1
32

nope

 

[deftron]

When I said "very tough math problem"

I should have said ""very tough problem for anyone who knows math"

 

[ribbon13]

My guess is then 73

 

[stringcheeseincident]

73.

 

[deftron]

people, you need to explain

 

[ribbon13]

I would have explained upon being correct.

 

[deftron]

Originally posted by: ribbon13
I would have explained upon being correct.

OK ... you are correct.

The answer is 73.

Do you know why?


BTW. nice Googling

 

[EngenZerO]

31

 

[ribbon13]

Google nothing, I contribute to AT&T R&D. It's a bookmark foo!

 

[EngenZerO]

how is it 73?

 

[deftron]

Well you still haven't explained..

 

[Otaking]

Originally posted by: Vaerilis
31

1 - 4 - 7
11 - 15 - 18
(2)1 - (2)4 - (2)7
(3)1 - (3)5 - (3)8

Probably.

That's amazing. Even though the answer was wrong, I never saw that pattern. :beer:

 

[deftron]

Originally posted by: Otaking

Originally posted by: Vaerilis
31

1 - 4 - 7
11 - 15 - 18
(2)1 - (2)4 - (2)7
(3)1 - (3)5 - (3)8

Probably.

That's amazing. Even though the answer was wrong, I never saw that pattern. :beer:

That's the obvoius (wrong) answer ...

 

[ribbon13]

a(n) when spelled is the smallest positive integer > a(n-1) with exactly n letters.

 

[EngenZerO]

" The Jan-Feb puzzle asked you to give the next item in this series:

1, 4, 7, 11, 15, 18, 21, 24, 27...

A bit of lateral thinking required here, as it was not really a Maths puzzle at all. The solution lies in the number of letters in the English names for these numbers. 73 (SEVENTYTHREE) is the answer "

http://www.bogle-dw.freeserve.co.uk/mtmt01.htm

 

[deftron]

Originally posted by: ribbon13
a(n) when spelled is the smallest positive integer > a(n-1) with exactly n letters.

Yeah ... like I said ... nice Googling

%S A084390 1,4,7,11,15,18,21,24,27,73,101,104,107,111,115,118,121,124,127,173,323,
%T A084390 373,1104,1107,1111,1115,1118,1121,1124,1127,1173,1323,1373,3323,3373,
%U A084390 11373,13323,13373,17373,23323,23373,73373,101373,103323,103373,111373
%N A084390 a(n), when spelled in English, is the smallest positive integer > a(n-1) with exactly n letters.
%C A084390 This uses the conventions that "and" is never used, and two-digit numbers are not used before "hundred". The sequence is labeled "finite" because there is no widely accepted naming convention for arbitrarily large numbers. - David Wasserman (wasserma(AT)spawar.navy.mil), Dec 20 2004
%H A084390 Author?, <a href="http://groups.google.com.au/groups?hl=e...3a57%2540posting.google.com%26rnum%3D6">Title?</a>
%H A084390 Author?, <a href="http://groups.google.com.au/groups?hl=e...%252C4%252C7%252C11%252C15%252C18%2522">Title?</a>
%e A084390 a(5) = 7 because 'seven' has 5 letters

Link



Even if you were part of that, you wouldn't use the same phrase verbatim :roll:

 

[ArmenK]

Originally posted by: deftron
When I said "very tough math problem"

I should have said ""very tough problem for anyone who knows math"

Why do you need to know math for this problem? If anything you need to not think about math to solve it since it requires counting letters in words.