Definition:Lychrel Number

Definition
A Lychrel number is a natural number which cannot form a palindromic number through repeated iteration of the reverse-and add process.

Also defined as
Some sources use the term Lychrel number to refer to numbers whose Lychrel status is unknown, that is, to candidate Lychrel numbers.

Others, referred to in some circles as purists, reserve the term Lychrel number for a candidate Lychrel number which cannot be obtained from a previous candidate Lychrel number during the course of a sequence of reverse-and add operations.

Such candidate Lychrel numbers can also be referred to as seed or root numbers Lychrel.

The candidate Lychrel numbers which can be derived from others can sometimes be found referred to as kin numbers.

Also see

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