Need help on Inhomogeneous Linear Recurrences an an1 3n1 a0

Need help on Inhomogeneous Linear Recurrences:

a_n = a_n-1 +3(n-1), a₀=1

Seeing the steps to solve it will help me get through the rest. Thanks for any help.

Solution

a_n = a_n-1 +3(n-1), a₀=1

put n=1

a₁ =a₀+0=1

a2=a1+3(2-1)=1+3=4

a3=a2+3(3-1)=4+6=10

a4=a3+3(4-1)=10+9=19

similarly solve all n vale

so series =1,4,10,19,21,..