if a1 = 4 and an = 3an - 1 + n then find the value of a3

Answer 1

a₁ = 4

a_n = 3a_n-1 + n

So, a₂ = 3a_2-1 + 2 = 3a₁ + 2 = 14

a₃ = 3a_3-1 + 3 = 3a₂ + 3 = 45

Answer 2

 a1 = 4 so a=4

and

an = 3an - 1 + n

A = 3N -1/N + 1

then find the value of a3; SO:

3A=9N-3/N+1