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

Author

Rémy Sigrist, Nov 11 2018

Keywords

• nonn
• base

Comments

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

Examples

			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.
		

Links

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

Crossrefs

Cf. A014190, A321464.

Programs

Mathematica

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

PARI

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