Update: I fixed my old MacBook to run this program and, by luck, the first number it found with over 180 "reverse and add to itself until it's a palindrome" iterations is 1107160000659887332018747, with 243 iterations, the same as my personal best from months ago!
Bonus: if you replace the "16" with "48" and replace the "201" with "682" in that number, it too results in the same palindromic number after 243 iterations. I've now got 3 personal bests!
NEW PERSONAL BEST: I've decided to go backwards from my start value and found my newest most delayed palindromic number: 1102320000659887332443347 takes 243 reverse-and-add iterations before it becomes a 123-digit palindrome!
This beats Jason Doucette's past world record on July 10, 2003 with 236 iterations (https://jasondoucette.com/worldrecords.html#Most). My new best record I've found is only 51 iterations from beating the current world record of 293.
#Math #Mathematics #MostDelayedPalindromicNumber #LychrelNumber
UPDATE: My program found a new personal best most delayed palindromic number!
The 25-digit number 1102320000659911613429286 takes 235 iterations before it becomes a 123-digit palindrome.
This beats a former world record set in 2003 by Jason Doucette involving 233 iterations (source: https://jasondoucette.com/worldrecords.html#Most), and is 58 iterations off from the current world record of 293.
#Math #LychrelNumber #MostDelayedPalindromicNumber #Mathematics #RecMath #RecreationalMathematics
Another update: Replacing the last 0 in the above number with a 9 and letting it follow the reverse-and-add process, it too takes 228 iterations before it reaches the same palindrome. Now I have two personal bests! 
UPDATE: New personal best delayed palindromic number discovered!
The 25-digit number 1702202577777781056628859 takes 228 "reverse and add" iterations before it reaches a 116-digit palindrome! It can be verified on https://www.dcode.fr/lychrel-number where you can see all the steps it takes!
That's 32 more iterations than my previous record, and 65 off from the current world record of 293. Awesome!!
#Math #LychrelNumber #MostDelayedPalindromicNumber #Mathematics
I've decided I'm gonna turn this into a thread and post every time my program discovers a new personal best delayed #LychrelNumber.
It recently discovered that 191220247777777777889829108 takes 196 "reverse and add" iterations before it becomes a palindrome! The number of iterations is ironic considering 196 itself is conjectured to be the first #LychrelNumber. Only 98 more iterations and it would've been a new world record!
Fun #math to try out:
A #LychrelNumber is any number that DOESN'T become a palindrome when you add itself to itself with its digits backwards repeatedly.
I wrote a Python script (see comments) to find numbers with ≥100 iterations before they become palindromes. I found the following requiring 150:
170000323160230112078861642
170000323160230112078886842
The world record most delayed palindrome, 1000206827388999999095750, requires 293 iterations:
MOULE 
