Answer
Given
$a_{n}$ = $a_{n - 1}$ + 3.
$a_{1}$, the first term = 4
$20^{th}$ term of sequence = 61
Work Step by Step
Given
$a_{n}$ = $a_{n - 1}$ + 3.
$a_{1}$, the first term = 4
$2^{nd}$ term of sequence = $a_{1}$ + 3 = 4 + 3 = 7
$3^{rd}$ term of sequence = $a_{2}$ + 3 = 7 + 3 = 10
$4^{th}$ term of sequence = $a_{3}$ + 3 = 10 + 3 = 13
$5^{th}$ term of sequence = $a_{4}$ + 3 = 13 + 3 = 16
$6^{th}$ term of sequence = $a_{5}$ + 3 = 16 + 3 = 19
$7^{th}$ term of sequence = $a_{6}$ + 3 = 19 + 3 = 22
$8^{th}$ term of sequence = $a_{7}$ + 3 = 22 + 3 = 25
$9^{th}$ term of sequence = $a_{8}$ + 3 = 25 + 3 = 28
$10^{th}$ term of sequence = $a_{9}$ + 3 = 28 + 3 = 31
$11^{th}$ term of sequence = $a_{10}$ + 3 = 31 + 3 = 34
$12^{th}$ term of sequence = $a_{11}$ + 3 = 34 + 3 = 37
$13^{th}$ term of sequence = $a_{12}$ + 3 = 37 + 3 = 40
$14^{th}$ term of sequence = $a_{13}$ + 3 = 40 + 3 = 43
$15^{th}$ term of sequence = $a_{14}$ + 3 = 43 + 3 = 46
$16^{th}$ term of sequence = $a_{15}$ + 3 = 46 + 3 = 49
$17^{th}$ term of sequence = $a_{16}$ + 3= 49 + 3 = 52
$18^{th}$ term of sequence = $a_{17}$ + 3 = 52 + 3 = 55
$19^{th}$ term of sequence = $a_{18}$ + 3 = 55 + 3 = 58
$20^{th}$ term of sequence = $a_{19}$ + 3 = 58 + 3 = 61
