Sequence Asking Out Of Box Thinking

Can you find what's next in this series?

1, 4, 11, 20, 31, 44, 61, ?


Not getting any clue, here I extend it little further.

1, 4, 11, 20, 31, 44, 61, 100, 121, 144, ? 

Now find what's next.

Note : This needs out of box thinking.

Out of Box Thinking

Couldn't find? Here is the answer!