Arithmetic Sequence and Series

Write the first 4 terms of $a_n=8n-1$  

 $Find\ \ the\ \ first\ \ 4\ \ terms\ for\ \ \ a_n=2\cdot a_{n-1}-4,\ \ if\ \ a_1=7$  

Write a formula for the general term of the arithmetic sequence 3,11,19, .....

 $Given\ a_n=-7n-4,\ find\ a_{30}.$  

Find the sum of the first 30 terms of -21+ -17 + -13 + .......

Find the sum of the following: -12 + -9+ -6 +....+333

Find the sum of the odd integers between 12 and 84.

 $What\ \ are\ \ the\ \ first\ \ 3\ \ terms\ \ of\ \ \sum_{n=1}^{20}-3n$  

 $What\ \ is\ \ the\ \ sum\ \ of\ \ \sum_{n=1}^{20}-3n$