1 5 9 15 _ (the next number in sequence is?)
I know the answer, challege is for the mathematicans who monitor Yahoo questions :^)
Facetiously, this is not a math sequence!
Good luck.
2007-01-05 07:00:08 · 14 answers · asked by srrl_ferroequinologist 3 in Science & Mathematics ➔ Mathematics
in response to alnitaka, I reply that it is a number sequence, with one answer determined by the information given
2007-01-05 08:36:16 · update #1
in response to alnitaka, I reply that it is a number sequence, with one answer determined by the information given
To Cheng J, I say hello as well.
2007-01-05 09:58:12 · update #2
21. Nice one there! :D Make more of them.
How bout 8 5 12 12 _ ? :D
2007-01-05 07:05:37 · answer #1 · answered by Cheng J 2 · 0⤊ 0⤋
If it's not a math sequence, then it should not be in the math category.
There are an infinite number of sequences that begin with 1, 5, 9, 15, and there does not seem to be universal criteria for deciding which is "correct". I can offer two possibilities:
21. This is assuming that you add 4, then 4, then 6, then 6, then 8, then 8, and so forth, repeating each even difference twice, yielding the sequence 1 5 9 15 21 29 37 47 57...
19. This is a set sequence. What are the subsets of {1, 5, 9}? Write it as 159, without the commas and braces. The set of all subsets is then 1 5 9 15 19 59 159. The sequence ends here - it is a finite sequence.
There are also other possibilities, as going to http://www.research.att.com/~njas/sequences/ and entering 1, 5, 9, 15 will show.
AFTERNOTE
I think I get it now. The answer is 18.
2007-01-05 07:35:16 · answer #2 · answered by alnitaka 4 · 1⤊ 0⤋
maybe
1 5 9 15 59 19 159 591 951
so the number is 59
2007-01-05 09:06:57 · answer #3 · answered by Beta01 3 · 0⤊ 0⤋
21
2007-01-05 07:07:42 · answer #4 · answered by firefreezed 2 · 0⤊ 0⤋
21
2007-01-05 07:02:53 · answer #5 · answered by Anonymous · 0⤊ 0⤋
actually it is 23.
1 5 9 15 23
you add even numbers such as
5+4 =9
9+6=15
15+8 = 23
the next number in the sequence is 33
2007-01-05 07:09:20 · answer #6 · answered by jack_daniels 5 · 0⤊ 1⤋
either 21 (assuming you add six) or 25, assuming the next would be a perfect square(p.s) then the sequence would be
1(p s),5 (one more than a p s),9(p s),15(one less than a p s) ,
25(p s),37(+1) ,49(p s),63( -1)
2007-01-05 08:52:57 · answer #7 · answered by lobster17 2 · 0⤊ 0⤋
91
keep repeating the 1-5-9 sequence....
2007-01-05 07:25:15 · answer #8 · answered by razor129 2 · 0⤊ 0⤋
59
2007-01-05 07:03:36 · answer #9 · answered by Jim C 4 · 1⤊ 0⤋
91
2007-01-05 07:09:00 · answer #10 · answered by killercrimson 2 · 0⤊ 0⤋