A054591 - OEIS

%I #25 Jan 05 2025 19:51:36

%S 1,3,4,9,10,12,13,27,28,30,36,39,40,81,82,84,90,91,108,117,120,121,

%T 146,182,205,243,244,246,252,270,273,324,328,351,360,363,364,386,438,

%U 546,615,656,671,729,730,732,738,756,757,810,819,820,949,972,984

%N Denominators of rational numbers that belong to the Cantor set.

%H David Radcliffe, <a href="/A054591/b054591.txt">Table of n, a(n) for n = 1..321</a>

%H D. Jordan and R. Schayer, <a href="https://math.psu.edu/mass/sites/default/files/reu2003/6.pdf">Rational points on the Cantor middle thirds set</a>, Penn State, REU 2003.

%H J. Nagy, <a href="https://web.archive.org/web/2024*/https://www.fq.math.ca/Scanned/39-3/nagy.pdf">Rational Points in Cantor Sets</a>, Fibonacci Quarterly 39.3, (2001), 238-241.

%H C. Wall, <a href="http://www.mathstat.dal.ca/FQ/Scanned/28-2/wall.pdf">Terminating Decimals in the Cantor Ternary Set</a>, Fibonacci Quarterly 28.2 (1990), 98-101.

%e 10 belongs to the sequence because 1/10 = 0.00220022... (base 3) is in the Cantor set. - _David Radcliffe_, May 02 2015

%Y Reminiscent of (but different from) A005836.

%K nonn,frac

%O 1,2

%A _Michael J. Hardy_, Apr 14 2000