nth term homework yr 7

[Christywhisty]

Ds has nth term as homework, most of it is okay and he understands it, fairly simple answers like 5n-2 etc

But the following just seem way too complicated

3,7, 11, 14, 18

the differences don't seem to make sense ( 4, 4, 3, 4,)

also

1, 8, 15, 22, 27

differences

(7, 7, 7, 5)

Any ideas, have tried squaring them etc
I am almost starting to think there are printing errors!

The first one is 4n - 1 until n is a multiple of 4 then it's 4n -2

until = unless

Thanks to everyone, I have told him to assume a typo and work it out that way

He should get the answers on Tuesday so will update what it should have been then.

Wow really impressed with DS's teacher, I emailed her last night and she has emailed me back this morning.

There were typing errors and she is telling the class today.

Thanks for all your and DC's help