What is the 45th term of the sequence 3, 7, 11, 15,...?

Answer 1

The series says that a₁ = 3

a₂ = a₁ + 4

a₃ = a₁ + 4 + 4 = a1 + 4(n-1) = 3 + 4(2) = 11

a₄ = a₁ + 4(4-1) = 3 + 12 = 15 etc

So,

a_n = a₁ + 4(n-1)

for the 45 term

a₄₅ = a₁ + 4(45-1) = 3 + 4(44) = 179