$a_n = 1.5 a_{n-1} + 2$ with $a_0 = 1$

$b_n = 0.7 b_{n-1} + 3$ with $b_0 = 1$

$c_n = c_{n-1} + n$ with $c_0 = 0$

$d_n = 2d_{n-1} - 0.8d_{n-2}$ with $d_0 = 1, d_1 = 1$