Lewis, Goodman and Miller (1969) suggested

• X_n+1 = 7⁵·X_n mod (2³¹-1)
• note:
  • 7⁵ is 16807
  • 2³¹-1 is 2147483647
  • X₀ = 0 is not a good seed value

Most compilers use LCG-based algorithms that are slightly more involved; see www.mscs.dal.ca/~selinger/random/ for details (including a short C program that produces the exact same pseudo-random numbers as gcc for any given seed value)