Pattern Detective! Part 1

Number Theory Level 1

What number comes next? 1 , 2 , 4 , 7 , 11 , ? 1, 2, 4, 7, 11, ?


The answer is 16.

Eric Hernandez by Eric Hernandez , 20, Mexico

This section requires Javascript.
You are seeing this because something didn't load right. We suggest you, (a) try refreshing the page, (b) enabling javascript if it is disabled on your browser and, finally, (c) loading the non-javascript version of this page . We're sorry about the hassle.

2 solutions

Renah Bernat
Oct 3, 2014

You can see that 1 +1 =2 , 2+2-4 , 4+3=7 , and 7+4=11. Therefore, it is logical the answer should be equal to 11+5=16.

0 Helpful 0 Interesting 0 Brilliant 0 Confused

I did it the same way.

Abdur Rehman Zahid - 6 years, 6 months ago
Eric Hernandez
Aug 14, 2014

You can see that 1 + 1 = 2 1+1=\color{#D61F06}{2} , 2 + 2 = 4 2+2=\color{#D61F06}{4} , 4 + 3 = 7 4+3=\color{#D61F06}{7} , and 7 + 4 = 11 7+\color{#D61F06}{4}=11 . Therefore, it is logical the answer should be equal to 11 + 5 = 16 11+\color{#69047E}{5}=16 .

The generating formula is: a n = n 2 − n + 2 2 a_{n}=\frac{n^{2}-n+2}{2} .

0 Helpful 0 Interesting 0 Brilliant 0 Confused

Thanks for adding solutions to your pattern recognition problems! It helps us understand how you arrived at the answers.

Calvin Lin Staff - 6 years, 10 months ago

0 pending reports

×

Problem Loading...

Note Loading...

Set Loading...