

A233572


In balanced ternary notation, if prepending same numbers of zeros, reverse digits of a(n) equals to a(n)


4



0, 2, 6, 8, 18, 20, 24, 26, 32, 54, 56, 60, 72, 78, 80, 96, 104, 146, 162, 164, 168, 180, 182, 216, 224, 234, 240, 242, 260, 288, 302, 312, 320, 338, 416, 438, 486, 488, 492, 504, 540, 546, 560, 648, 656, 672, 702, 720, 726, 728, 780, 800, 864, 896, 906, 936
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OFFSET

1,2


COMMENTS

A233571 is a subset of this sequence.


LINKS

Lei Zhou, Table of n, a(n) for n = 1..10000


EXAMPLE

In balanced ternary notation, 18 = (1T00)_bt, where we use T to represent 1. Patching two zeros before it, (1T00)_bt=(001T00)_bt. The reverse digits of (001T00)_bt is (00T100)_bt = 18. So 18 is in this sequence.


MATHEMATICA

BTDigits[m_Integer, g_] :=
Module[{n = m, d, sign, t = g},
If[n != 0, If[n > 0, sign = 1, sign = 1; n = n];
d = Ceiling[Log[3, n]]; If[3^d  n <= ((3^d  1)/2), d++];
While[Length[t] < d, PrependTo[t, 0]]; t[[Length[t] + 1  d]] = sign;
t = BTDigits[sign*(n  3^(d  1)), t]]; t];
BTrteQ[n_Integer] :=
Module[{t, trim = n/3^IntegerExponent[n, 3]},
t = BTDigits[trim, {0}]; DeleteDuplicates[t + Reverse[t]] == {0}];
sb = Select[Range[0, 950], BTrteQ[#] &]


CROSSREFS

Cf. A002113, A061917, A006995, A057890, A134027, A233010, A233571
Sequence in context: A183212 A325686 A053355 * A005823 A259026 A178758
Adjacent sequences: A233569 A233570 A233571 * A233573 A233574 A233575


KEYWORD

nonn,base


AUTHOR

Lei Zhou, Dec 13 2013


STATUS

approved



