Sequence Question

Question: What's the next term in the following sequence: 1, 11, 21, 1211, 111221, 312211, ?

The trick to answering this question is to recognize that each value in the sequence describes the value before it.

term_1 = 1

To determine the value of term_2, we need to examine term_1.

In term_1, we have one 1 (1 1), which we'll write as 11.

So, term_2 = 11

To determine the value of term_3, we need to examine term_2.

In term_2, we have two 1's (2 1's), which we'll write as 21.

So, term_3 = 21

To determine the value of term_4, we need to examine term_3.

In term_3, we have one 2, followed by one 1, which we'll write as 1211.

So, term_4 = 1211

In term_4, we have one 1, followed by one 2, followed by two 1's, which we'll write as 111221.

So, term_5 = 111221

In term_5, we have three 1's, followed by two 2's, followed by one 1, which we'll write as 312211.

So, term_6 = 312211

In term_6, we have one 3, followed by one 1, followed by two 2's, followed by two 1's, which we'll write as 13112221.

So, term_7 = 13112221

Answer: 13112221