Question

write the nth term of the sequence 1, 4, 9, 16

Answer 1

\[\sum_{k=1}^{n}2(k-1)+1\]

Answer 2

What does that notation mean?

Answer 3

the nth term is n^2

Answer 4

since 1^2=1, 2^2=4, 3^2=9, 4^2=16,...,n^2

Answer 5

so what would the nth term be?

Answer 6

oh n^2 ok

Answer 7

What about the sequence 3, 11, 31, 69, 131

Answer 8

anyone there

Answer 9

myininaya are you there?

Answer 10

I'm trying to see the pattern

Answer 11

The first differences would be 3, 20, 38, 62. The second differences would be 12, 18, 23 and 30. The third difference would be 6 for all of them

Answer 12

Oh I meant 24 not 23

Answer 13

Are you still there?

Answer 14

That's funny. Both answers are correct.

My answer was that the nth term was the sum of the first n odd natural numbers.

So the first number is
1, the second is 1+3=4, the third is 1+3+5=9, the fourth is 1+3+5+7 = 16

Answer 15

polpak did you get my second question?

Answer 16

Yeah, looking at it, but these things are kinda lame cause there's a lot of different ways you can approach it.

Answer 17

ok. tell me when you have an answer

Answer 18

I don't get this stuff.