A354886 - OEIS

%I #15 Jun 16 2022 02:33:34

%S 16,52,160,484,1312,1456,3904,4372,11680,12688,13120,35008,37960,

%T 39364,104992,106288,113776,116800,118096,314944,319156,341224,350080,

%U 354292,944800,948688,957760,1023568,1027456,1049920,1058992,1062880,2834368,2847004,2873572

%N Numbers that are palindromes in both ternary and balanced ternary representations with representations that are different.

%C Is a(n) == 16 (mod 18) for all n?

%H Amiram Eldar, <a href="/A354886/b354886.txt">Table of n, a(n) for n = 1..10000</a>

%F a(n) = A091077(n) / 4. - _Hugo Pfoertner_, Jun 10 2022

%e 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.

%t Select[Range[0, 3*10^6], PalindromeQ[d3 = IntegerDigits[#, 3]] && PalindromeQ[db3 = balTernDigits[#]] && d3 != db3 &] (* using balTernDigits by _Robert G. Wilson v_ at A134027 *)

%Y Equals A354885 \ A005836.

%Y Cf. A007089, A014190, A091077, A134027, A140267.

%K nonn,base

%O 1,1

%A _Amiram Eldar_, Jun 10 2022