and its final term. On 26 April 2019, Rob van Nobelen computed a new world record for the Most Delayed Palindromic Number: 12,000,700,000,025,339,936,491 takes 288 iterations to reach a 142 digit palindrome 6634343445544188178365154497662249922269477578658488045222897505659677887769565057982225408848568757749622299422667944515638718814455443434366. On 5 January 2021, Anton Stefanov computed two new Most Delayed Palindromic Numbers: 13968441660506503386020 and 13568441660506503386420 takes 289 iterations to reach the same 142 digit palindrome as the Rob van Nobelen number. On December 14, 2021, Dmitry Maslov computed a new world record for the Most Delayed Palindromic Number: 1,000,206,827,388,999,999,095,750 takes 293 iterations to reach 132 digit palindrome 880226615529888473330265269768646444333433887733883465996765424854458424567699564388337788334333444646867962562033374888925516622088 The OEIS sequence A326414 contains 19353600 terms with 288-step delay known at present. Any number from A281506 could be used as a primary base to construct higher order 261-step palindromes. For example, based on 1,999,291,987,030,606,810 the following number 199929198703060681000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000001999291987030606810 also becomes a 238-digit palindrome 44562665878976437622437848976653870388884783662598425855963436955852489526638748888307835667984873422673467987856626544 44562665878976437622437848976653870388884783662598425855963436955852489526638748888307835667984873422673467987856626544 after 261 steps. The smallest number that is not known to form a palindrome is 196. It is therefore the smallest Lychrel number candidate. The number resulting from the reversal of the digits of a Lychrel number not ending in zero is also a Lychrel number. Formal definition of the process Let be a natural number. We define the Lychrel function for a number base b > 1, , to be the following: where is the number of digits in the number in base , and is the value of each digit of the number. A number is a Lychrel number if there does not exist a natural number such that , where is the -th iteration of Proof not found In other bases (these bases are powers of 2, like binary and hexadecimal), certain numbers can be proven to never form a palindrome after repeated reversal and addition, but no such proof has been found for 196 and other base 10 numbers. It is conjectured that 196 and other numbers that have not yet yielded a palindrome are Lychrel numbers, but no number in base ten has yet been proven to be Lychrel. Numbers which have not been demonstrated to be non-Lychrel are informally called "candidate Lychrel" numbers. The first few candidate Lychrel numbers are: 196, 295, 394, 493, 592, 689, 691, 788, 790, 879, 887, 978, 986, 1495, 1497, 1585, 1587, 1675, 1677, 1765, 1767, 1855, 1857, 1945, 1947, 1997. The numbers in bold are suspected Lychrel seed numbers (see below). Computer programs by Jason Doucette, Ian Peters and Benjamin