What are the first five terms of the sequence defined by the formula an = 4n + 1?

To find the first five terms of the sequence given by the formula a_n = 4n + 1, we need to substitute values of n starting from 1 and increasing by 1 until we reach 5.

1. For n = 1:
   a₁ = 4(1) + 1 = 4 + 1 = 5
2. For n = 2:
   a₂ = 4(2) + 1 = 8 + 1 = 9
3. For n = 3:
   a₃ = 4(3) + 1 = 12 + 1 = 13
4. For n = 4:
   a₄ = 4(4) + 1 = 16 + 1 = 17
5. For n = 5:
   a₅ = 4(5) + 1 = 20 + 1 = 21

Thus, the first five terms of the sequence are:

• a₁ = 5
• a₂ = 9
• a₃ = 13
• a₄ = 17
• a₅ = 21

In conclusion, the first five terms of the sequence defined by the formula a_n = 4n + 1 are 5, 9, 13, 17, and 21.