A321473 Nonnegative numbers whose nonzero digits in ternary expansion are palindromic.

0, 1, 2, 3, 4, 6, 8, 9, 10, 12, 13, 16, 18, 20, 23, 24, 26, 27, 28, 30, 31, 34, 36, 37, 39, 40, 46, 48, 52, 54, 56, 59, 60, 62, 65, 68, 69, 72, 74, 78, 80, 81, 82, 84, 85, 88, 90, 91, 93, 94, 100, 102, 106, 108, 109, 111, 112, 117, 118, 120, 121, 130, 136, 138

Offset

1,3

Comments

This sequence corresponds to the fixed points of A321464, and contains A014190.

Links

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

Example

For n = 1594426:
- the ternary expansion of 1594426 is "10000000010211",
- the corresponding nonzero digits are "11211", which are palindromic,
- hence 1594426 belongs to the sequence.

Mathematica

Select[Range[0, 200], PalindromeQ[FromDigits[IntegerDigits[#, 3]/.(0-> Nothing)]]&] (* Requires Mathematica version 10 or later *) (* Harvey P. Dale, Jun 22 2020 *)

Prog

(PARI) is(n, base=3) = my (t=select(sign, digits(n, base))); t==Vecrev(t)

Crossrefs

Cf. A014190, A321464.

Sequence in context: A026433 A354148 A015858 * A125292 A101513 A153276

Adjacent sequences: A321470 A321471 A321472 * A321474 A321475 A321476

Keyword

nonn,base

Author

Rémy Sigrist, Nov 11 2018

Status

approved