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A321473
Nonnegative numbers whose nonzero digits in ternary expansion are palindromic.
2
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
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
Sequence in context: A026433 A354148 A015858 * A125292 A101513 A153276
KEYWORD
nonn,base
AUTHOR
Rémy Sigrist, Nov 11 2018
STATUS
approved