Question 1165212
<pre>
20
20+10=30
30-5=25
25+10=35
35-5=30
30+10=40
40-5=35

20,30,25,35,30,40,35,45,40,50,45,55,50,60,55,65,60,70,65,75,...

The general term is

{{{a[n]=expr(5/4)(2n+17+3(-1)^n)}}}

If you want me to show you how I got that general term, ask me
in the space below, and I'll get back to you by email.

Edwin</pre>