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

105956506309091459564960, 53528258705040674282425, 31769674352025337585712, 53528258709000674282425, 53528298705040670282425, 53528298709000670282425, 53928258705040674282025, 53928258709000674282025, 53928298705040670282025, 31564654352025334636412

Offset: 1

Author

Anton Stefanov, Jan 06 2021

Keywords

• nonn
• base
• fini

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

• Anton Stefanov, Table of n, a(n) for n = 1..20
• Jason Doucette and Anton Stefanov, Final 289 steps World Record proof with some numeric generators of delayed palindromes inside
• Anton Stefanov, Extending the method of undetermined coefficients
• Anton Stefanov, isExtends test realisation on C# (to verify A340397 elements)

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.