In mathematics, the beth numbers are a certain sequence of infinite cardinal numbers, conventionally written ℶ 0 , ℶ 1 , ℶ 2 , ℶ 3 , … {displaystyle eth _{0}, eth _{1}, eth _{2}, eth _{3}, dots } , where ℶ {displaystyle eth } is the second Hebrew letter (beth). The beth numbers are related to the aleph numbers ( ℵ 0 , ℵ 1 , … {displaystyle aleph _{0}, aleph _{1}, dots } ), but there may be numbers indexed by ℵ {displaystyle aleph } that are not indexed by ℶ {displaystyle eth } . In mathematics, the beth numbers are a certain sequence of infinite cardinal numbers, conventionally written ℶ 0 , ℶ 1 , ℶ 2 , ℶ 3 , … {displaystyle eth _{0}, eth _{1}, eth _{2}, eth _{3}, dots } , where ℶ {displaystyle eth } is the second Hebrew letter (beth). The beth numbers are related to the aleph numbers ( ℵ 0 , ℵ 1 , … {displaystyle aleph _{0}, aleph _{1}, dots } ), but there may be numbers indexed by ℵ {displaystyle aleph } that are not indexed by ℶ {displaystyle eth } .