The recursive formula of the arithmetic sequence is
[tex]a_n=a_{n-1}+d[/tex]Where d is the common difference between each 2 consecutive terms
The explicit form of the arithmetic sequence is
[tex]a_n=a+(n-1)d[/tex]a is the first term
d is the common difference
Since the given explicit form of the sequence is
[tex]a_n=13+(n-1)6[/tex]Then
a = 13
d = 6
The recursive form of the sequence should be
[tex]a_n=a_{n-1}+6[/tex]The missing number is 6
The answer is D