Tribonacci

Blend of tri- +‎ Fibonacci

Tribonacci

1. (mathematics) A variant of the Fibonacci sequence in which the preceding three terms, rather than the preceding two, are summed at each iteration.
   • 2016, John Aycock, Retrogame Archeology, Springer, →ISBN, page 113:

     Elite uses a pseudorandom number generator based on Tribonacci numbers. Unlike Fibonacci numbers, where the nth term in the series is based on the previous two terms, Tribonacci numbers use the previous three terms: […]

• carbonitic