Identify the first five terms of the sequence in which an = 3n − 1 + 1.

1, 4, 16, 64, 256
1, 4, 7, 10, 13
2, 4, 32, 512, 1024
2, 4, 10, 28, 82

4 answers

really? Just plug in n=1,2,3,4,5
a1 = 3*1-1+1 = 3
and so on.

I suspect you have made a typo, since 3n-1+1 is kinds lame, and matches none of the choices.
Is that supposed to be 3^(n-1) + 1?
Whatever it should be, make the fix and then just plug and chug
yes i meant 3^(n-1) + 1
sorry
an = 3 ∙ ( n - 1 ) + 1

n = 1

a1 = 3 ∙ ( 1 - 1 ) + 1 = 3 ∙ 0 + 1 = 0 + 1 = 1

a2 = 3 ∙ ( 2 - 1 ) + 1 = 3 ∙ 1 + 1 = 3 + 1 = 4

a3 = 3 ∙ ( 3 - 1 ) + 1 = 3 ∙ 2 + 1 = 6 + 1 = 7

a4 = 3 ∙ ( 4 - 1 ) + 1 = 3 ∙ 3 + 1 = 9 + 1 = 10

a5 = 3 ∙ ( 5 - 1 ) + 1 = 3 ∙ 4 + 1 = 12 + 1 = 13

1 , 4 , 10 , 7 , 13
thank you bosnian