For Case 1, when m is even,
the equation is given as 8f(m + 1) - f(m) = 2.
⇒ 8( m + 1 + 3) - m(m + 1) = 2
⇒ 8m + 32 - m² - m = 2
⇒ m² - 7m + 30 = 0
⇒ (m - 10)(m + 3) = 0
⇒ m = 10 or -3
Since m must be a positive integer, the only valid solution is m = 10.
In Case 2, when m is odd, there is no positive solution for the given equation.