cp's OEIS Frontend

This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.

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A340397 Complete sequence of numeric generators of delayed palindromes used to get 289-step delayed palindromes.

Original entry on oeis.org

105956506309091459564960, 53528258705040674282425, 31769674352025337585712, 53528258709000674282425, 53528298705040670282425, 53528298709000670282425, 53928258705040674282025, 53928258709000674282025, 53928298705040670282025, 31564654352025334636412
Offset: 1

Views

Author

Anton Stefanov, Jan 06 2021

Keywords

Comments

The terms of this sequence are based on the terms of A326414 and are used to extend 288-step delayed palindromes up to 289-step delayed palindromes with the help of brute force extension of the method of undetermined coefficients.

Examples

			The 285-step delayed palindrome 105956506309091459564960 can be extended to the 286-step delayed palindrome 53528258705040674282425, which in turn can be extended to the 287-step delayed palindrome 31769674352025337585712. This 287-step solution is unextendable so we start a new branch from the 286-step solution 53528258709000674282425 which also extends the first term of our sequence, and so on.

Links

Crossrefs

A326414 contains two numeric generators of delayed palindromes from our sequence: 16232852231012114813251 and 16232892231012110813251.
A072216 contains delayed palindromes of n digits with the greatest number of steps to converge.
A065199 contains records for the number of 'Reverse and Add' steps needed to reach a palindrome.
A065198 contains the most delayed palindromes in the order of their discovery and gives the starting points for the corresponding elements of the sequence A065199.

A353185 Numbers which require exactly 289 'Reverse and Add' steps to reach a palindrome.

Original entry on oeis.org

10037000230509917799950, 10037000240508917799950, 10037000250507917799950, 10037000260506917799950, 10037000270505917799950, 10037000280504917799950, 10037000290503917799950, 10037000330509817799950, 10037000340508817799950
Offset: 1

Views

Author

Andrey S. Shchebetov and Sergei D. Shchebetov, Apr 29 2022

Keywords

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

Crossrefs

A023109, A033672, A065198, A065199, A065320, A065321, A065322, A065323, A065324, A065325, A065326, A065327, A070743, A072216, A072217, A072218, A281301, A281390, A281506, A281507, A326414.

Formula

Each term requires exactly 289 steps to turn into a 142-digit palindrome.
Showing 1-2 of 2 results.

Started in 1964 by Neil J. A. Sloane | Maintained by The OEIS Foundation Inc.

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