A Tribonacci-like sequence of composite numbers
Journal of integer sequences, Tome 20 (2017) no. 3
We find a new Tribonacci-like sequence of positive integers 〈 $x_{0}, x_{1}, x_{2}, \dots $〉 given by $x_{n} = x_{n-1} + x_{n-2} + x_{n-3}, n \ge 3$, and $gcd(x_{0},x_{1},x_{2}) = 1$ that contains no prime numbers. We show that the sequence with initial values $x_{0} = 151646890045, x_{1} = 836564809606, x_{2} = 942785024683$ is the current record in terms of the number of digits.
@article{JIS_2017__20_3_a4,
author = {Lunev, Ivan},
title = {A {Tribonacci-like} sequence of composite numbers},
journal = {Journal of integer sequences},
year = {2017},
volume = {20},
number = {3},
zbl = {1381.11013},
language = {en},
url = {http://geodesic.mathdoc.fr/item/JIS_2017__20_3_a4/}
}
Lunev, Ivan. A Tribonacci-like sequence of composite numbers. Journal of integer sequences, Tome 20 (2017) no. 3. http://geodesic.mathdoc.fr/item/JIS_2017__20_3_a4/