A302663 Lexicographically first sequence of distinct terms such that the absolute differences |a(n) - a(n+1)| are A002113(n+1), where A002113 is "the palindromes in base 10".

1, 2, 4, 7, 3, 8, 14, 21, 13, 22, 11, 33, 66, 110, 55, 121, 44, 132, 231, 130, 19, 140, 9, 150, 301, 462, 291, 472, 281, 483, 271, 493, 261, 503, 251, 513, 241, 523, 815, 512, 199, 522, 189, 532, 179, 542, 169, 552, 159, 563, 149, 573, 139, 583, 129, 593, 119, 603, 109, 614, 99, 624, 89, 634, 79, 644

Offset

1,2

Comments

The sequence starts with a(1) = 1 and is always extended with the smallest integer not yet present that doesn't lead to a contradiction.

Links

Jean-Marc Falcoz, Table of n, a(n) for n = 1..2229

Example

|1 - 2| = 1, which is the 2nd palindrome of A002113 (the 1st one being "0");
|2 - 4| = 2 which is the 3rd palindrome;
|4 - 7| = 3 which is the 4th palindrome;
|7 - 3| = 4 which is the 5th palindrome;
|3 - 8| = 5 which is the 6th palindrome;
|8 - 14| = 6 which is the 7th palindrome;
|14 - 21| = 7 which is the 8th palindrome;
|21 - 13| = 8 which is the 9th palindrome;
|13 - 22| = 9 which is the 10th palindrome;
|22 - 11| = 11 which is the 11th palindrome;
|11 - 33| = 22 which is the 12th palindrome; etc.

Crossrefs

Cf. A002113 (palindromes in base 10).

Sequence in context: A084332 A081145 A100707 * A078943 A063733 A187089

Adjacent sequences: A302660 A302661 A302662 * A302664 A302665 A302666

Keyword

nonn,base

Author

Eric Angelini and Jean-Marc Falcoz, Apr 11 2018

Status

approved