Friday, September 22, 2017

Subtracting with Exponents

If you take a lot of numbers and then square them and them subtract the result of each number from the one above it you will notice a pattern.

1²=1     4-1=3
2²=4     9-4=5
3²=9     16-9=7
4²=16     25-16=9
5²=25     36-25=11
6²=36     49-36=13
7²=49     64-49=15
8²=64     81-64=17
9²=81     100-81=19
10²=100

Every time the number you are going up by is increasing by 2. That phrase sounds a lot like my last post. So, let's see if there's something similar for the cubes.
1³=1     8-1=7
2³=8     27-8=19
3³=27     64-27=37
4³=64     125-64=61
5³=125     216-125=91
6³=216     343-216=127
7³=343     512-343=169
8³=512     729-512=217
9³=729     1,000-729=271
10³=1,000
This looks a lot like the exponents from before, except different numbers. So maybe we need to do it again?

19-7=12     127-91=36
37-19=18     169-127=42
61-37=24     217-169=48
91-61=30     271-217=54
It worked! We have the numbers which are increasing by a number again. The difference is that this time it's 6. So it's probably either going up by 4 or multiplying by 3. I'll do one more to see, though I'll probably have to subtract 3 times this time.
14=1     16-1=15     65-15=40     110-40=70     84-70=14
24=16     81-16=65     175-65=110     194-110=84     108-84=20
34=81     256-81=175     369-175=194     302-194=108     132-108=24
44=256     625-256=369     671-369=302     434-302=132     156-132=24
54=625     1,296-625=671     1,105-671=434     590-434=156     180-156=24
64=1,296     2,401-1,296=1,105     1,695-1,105=590     770-590=180     204-180=24
74=2,401     4,096-2,401=1,695     2,465-1,695=770     974-770=204
84=4,096     6,561-4,096=2,465     3,439-2,465=974
94=6,561     10,000-6,561=3,439
104=10,000

Well, I had to do 4 subtractions instead of the 3 I anticipated and something unexpected happened. After 2 numbers it got stuck in a rut of 24. I'll see what happens if I add the 11th number.
114=14,641. 14,641-10,000=4,641. 4,641-3,439=1,202. 1,202-974=228. 228-204=24!
Well, I think it's broken. If you want to do the next stage, do it, but since it might be 8 subtractions, it will be a lot of work. I'm not going to do it, but if you do, please post your findings in a comment for this post.

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