Question

I don't understand how it's wrong??

Answer 1

$a_1=4\\a_n=10-3a_{n-1}\\\\a_2=10-3a_1\to a_2=10-3(4)=10-12=-2\\\\a_3=10-3a_2\to a_3=10-3(-2)=10+6=16\\\\a_4=10-3a_3\to a_4=10-3(16)=10-48=-38\\\\a_5=10-3a_4\to a_5=10-3(-38)=10+114=124\\\\\underline{\text{..n..|..1..|..2..|...3...|...4...|...5...}}\\a_n\ \ \text{|..4..|.-2..|..16..|.-38.|..124}$