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A353185 Numbers which require exactly 289 'Reverse and Add' steps to reach a palindrome. 1
10037000230509917799950, 10037000240508917799950, 10037000250507917799950, 10037000260506917799950, 10037000270505917799950, 10037000280504917799950, 10037000290503917799950, 10037000330509817799950, 10037000340508817799950 (list; graph; refs; listen; history; text; internal format)
OFFSET
1,1
COMMENTS
The sequence starts with 10037000230509917799950, ends with 15999771990503200073000 and contains 9031680 terms known at present, including 13968441660506503386020 and 13568441660506503386420 discovered by Anton Stefanov on January 5, 2021.
REFERENCES
Popular Computing (Calabasas, CA), The 196 Problem, Vol. 3 (No. 30, Sep 1975).
LINKS
Sergei D. Shchebetov, Table of n, a(n) for n = 1..10000
Jason Doucette, World Records
Yutaka Nishiyama, Numerical Palindromes and the 196 Problem, International Journal of Pure and Applied Mathematics, Volume 80, No. 3, 2012, 375-384.
Sergei D. Shchebetov, 9031680 terms (zipped file)
R. Styer, The Palindromic Conjecture and the Fibonacci Sequence, Villanova University, 1986, 1-11.
C. W. Trigg, Palindromes by Addition, Mathematics Magazine, 40 (1967), 26-28.
C. W. Trigg, More on Palindromes by Reversal-Addition, Mathematics Magazine, 45 (1972), 184-186.
Wikipedia, Lychrel Number
196 and Other Lychrel Numbers, 196 and Lychrel Number
FORMULA
Each term requires exactly 289 steps to turn into a 142-digit palindrome.
CROSSREFS
Sequence in context: A343266 A330009 A171265 * A180247 A095440 A326414
KEYWORD
nonn,base
AUTHOR
Andrey S. Shchebetov and Sergei D. Shchebetov, Apr 29 2022
STATUS
approved

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Last modified February 23 11:05 EST 2024. Contains 370283 sequences. (Running on oeis4.)