As for this question you can see that the triangles in the sequence each get incremented by 3 for each term. The first one has 1, the second one has 4, the third one has 7 and so on. So judging by this sequence if this continues to the 7th term you will end up with 16. The second has 4, the third has 7, the fourth has 10, the fifth has 13, and the sixth has 16 and finally you get 19 as your 7th term! I hope this answer helped your question! :)
