

A354885


Numbers that are palindromes in both ternary and balanced ternary representations.


2



0, 1, 4, 10, 13, 16, 28, 40, 52, 82, 91, 112, 121, 160, 244, 280, 328, 364, 484, 730, 757, 820, 847, 976, 1003, 1066, 1093, 1312, 1456, 2188, 2296, 2440, 2548, 2920, 3028, 3172, 3280, 3904, 4372, 6562, 6643, 6832, 6913, 7300, 7381, 7570, 7651, 8752, 8833, 9022
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OFFSET

1,3


LINKS



EXAMPLE

4 is a term since its ternary and balanced ternary representation are both 11 which is a palindrome.
16 is a term since its ternary representation is 121 and its balanced ternary representation (with 2 standing for the 1 digit) is 1221, and both are palindromes.


MATHEMATICA

Select[Range[0, 10^4], PalindromeQ[IntegerDigits[#, 3]] && PalindromeQ @ balTernDigits[#] &] (* using balTernDigits by Robert G. Wilson v at A134027 *)


PROG

(PARI) is(n) = {my (t=digits(n, 3)); if (t==Vecrev(t), my (b=[], d); while (n, b=concat(d=[0, 1, 1][1+n%3], b); n=(nd)/3); b==Vecrev(b), 0)} \\ Rémy Sigrist, Jun 10 2022


CROSSREFS



KEYWORD

nonn,base


AUTHOR



STATUS

approved



