Hitting k primes by dice rolls

Fuente: arXiv
Saved in:
Bibliographic Details
Main Authors: Alon, Noga, Malinovsky, Yaakov, Martinez, Lucy, Zeilberger, Doron
Format: Preprint
Published: 2025
Subjects:
Online Access:
Tags: Add Tag
No Tags, Be the first to tag this record!
_version_ 1866929711686352896
author Alon, Noga
Malinovsky, Yaakov
Martinez, Lucy
Zeilberger, Doron
author_facet Alon, Noga
Malinovsky, Yaakov
Martinez, Lucy
Zeilberger, Doron
contents Let $S=(d_1,d_2,d_3, \ldots )$ be an infinite sequence of rolls of independent fair dice. For an integer $k \geq 1$, let $L_k=L_k(S)$ be the smallest $i$ so that there are $k$ integers $j \leq i$ for which $\sum_{t=1}^j d_t$ is a prime. Therefore, $L_k$ is the random variable whose value is the number of dice rolls required until the accumulated sum equals a prime $k$ times. It is known that the expected value of $L_1$ is close to $2.43$. Here we show that for large $k$, the expected value of $L_k$ is $(1+o(1)) k\log_e k$, where the $o(1)$-term tends to zero as $k$ tends to infinity. We also include some computational results about the distribution of $L_k$ for $k \leq 100$.
format Preprint
id arxiv_https___arxiv_org_abs_2502_08096
institution arXiv
publishDate 2025
record_format arxiv
spellingShingle Hitting k primes by dice rolls
Alon, Noga
Malinovsky, Yaakov
Martinez, Lucy
Zeilberger, Doron
Probability
Combinatorics
Number Theory
60C05, 11A41, 60G40
Let $S=(d_1,d_2,d_3, \ldots )$ be an infinite sequence of rolls of independent fair dice. For an integer $k \geq 1$, let $L_k=L_k(S)$ be the smallest $i$ so that there are $k$ integers $j \leq i$ for which $\sum_{t=1}^j d_t$ is a prime. Therefore, $L_k$ is the random variable whose value is the number of dice rolls required until the accumulated sum equals a prime $k$ times. It is known that the expected value of $L_1$ is close to $2.43$. Here we show that for large $k$, the expected value of $L_k$ is $(1+o(1)) k\log_e k$, where the $o(1)$-term tends to zero as $k$ tends to infinity. We also include some computational results about the distribution of $L_k$ for $k \leq 100$.
title Hitting k primes by dice rolls
topic Probability
Combinatorics
Number Theory
60C05, 11A41, 60G40
url https://arxiv.org/abs/2502.08096