A118597 Palindromes in base 6 (written in base 6).

0, 1, 2, 3, 4, 5, 11, 22, 33, 44, 55, 101, 111, 121, 131, 141, 151, 202, 212, 222, 232, 242, 252, 303, 313, 323, 333, 343, 353, 404, 414, 424, 434, 444, 454, 505, 515, 525, 535, 545, 555, 1001, 1111, 1221, 1331, 1441, 1551, 2002, 2112, 2222, 2332, 2442, 2552

Offset

1,3

Comments

Also palindromes with no digit greater than 5. - Harvey P. Dale, Nov 26 2019

Links

Harvey P. Dale, Table of n, a(n) for n = 1..1000

Mathematica

(* get NextPalindrome from A029965 *) Select[NestList[NextPalindrome, 0, 125], Max@IntegerDigits@# < 6 &] (* Robert G. Wilson v, May 09 2006 *)
Select[FromDigits/@Tuples[Range[0, 5], 4], PalindromeQ] (* Requires Mathematica version 10 or later *) (* Harvey P. Dale, Nov 26 2019 *)

Prog

(Python)
from sympy import integer_log
from gmpy2 import digits
def A118597(n):
    if n == 1: return 0
    y = 6*(x:=6**integer_log(n>>1, 6)[0])
    return int((s:=digits(n-x, 6))+s[-2::-1] if n<x+y else (s:=digits(n-y, 6))+s[::-1]) # Chai Wah Wu, Jun 14 2024

Crossrefs

Cf. A029953, A057148, A118594, A118595, A118596, A118597, A118598, A118599, A118600, A002113.

Sequence in context: A116067 A063685 A006481 * A083160 A123823 A274837

Adjacent sequences: A118594 A118595 A118596 * A118598 A118599 A118600

Keyword

nonn,base

Author

Martin Renner, May 08 2006

Extensions

Corrected and extended by Robert G. Wilson v, May 09 2006

Status

approved