OFFSET

1,2

LINKS

Giorgos Kalogeropoulos, Table of n, a(n) for n = 1 to 9999

Eric Angelini, Palindromaniac, Personal blog, April 2024.

EXAMPLE

The 1st pair of terms (1,221) and the 2nd one (12,21) share the same palindromic digit succession.

The 3rd pair of terms (2,332) and the 4th one (23,32) share the same palindromic digit succession.

The 5th pair of terms (3,113) and the 6th one (31,13) share the same palindromic digit succession. Etc.

MATHEMATICA

lst={1}; Do[While[f=Flatten[IntegerDigits/@{Last@lst, k}];

f1=First@SortBy[Select[Table[FromDigits/@TakeDrop[f, m], {m, Length@f-1}], ContainsNone[lst, #]&], First];

!ListQ@f1||MemberQ[lst, k]||ContainsAny[lst, f1]||Equal@@f1||!PalindromeQ@f, k++];

lst=Join[lst, {k}, f1]; k=1; While[MemberQ[lst, k], k++]; AppendTo[lst, k], {w, 20}]; lst

CROSSREFS

KEYWORD

AUTHOR

Eric Angelini and Giorgos Kalogeropoulos, Apr 11 2024

STATUS

approved