[填空题]
The table shows the first fouu4hf8rb--,q+j xmb)femo p9eo ch 6q+r terms oeu)xsts08u (pf three sequences: $u_n$ , $v_n$ , and $w_n$.
1.State which sequence is
1.1.arithmetic is ;
1.2.geometric is .
2.Find the sum of the first 50 terms of the arithmetic sequence.
$S_{50}$= .
3.Find the exact value of the 13th term of the geometric sequence