login
The OEIS is supported by the many generous donors to the OEIS Foundation.

 

Logo
Hints
(Greetings from The On-Line Encyclopedia of Integer Sequences!)
A118561 Lucky numbers for which the reversal is also a lucky number. 4

%I #20 Nov 18 2019 03:21:00

%S 1,3,7,9,13,15,31,33,37,51,73,99,111,115,133,141,151,163,169,171,189,

%T 193,195,303,327,331,339,361,385,391,393,399,511,529,535,537,579,583,

%U 591,717,723,727,729,735,739,777,787,925,927,933,937,961,975,979,981,993

%N Lucky numbers for which the reversal is also a lucky number.

%H Amiram Eldar, <a href="/A118561/b118561.txt">Table of n, a(n) for n = 1..10000</a> (terms 1..9014 from T. D. Noe)

%H W. Schneider, <a href="http://web.archive.org/web/2004/www.wschnei.de/number-theory/lucky-numbers-list.html">The First 1,000 Lucky Number</a>.

%e 133 is in the sequence because (1) it is a lucky number and (2) the reversal 331 is also a lucky number.

%t nn = 10^3; t = Range[1, nn, 2]; sieve[n_] := Module[{k = t[[n]]}, t = Delete[t, Table[{i}, {i, k, Length[t], k}]]]; n = 1; While[t[[n]] < Length[t], n++; sieve[n]]; tr = Table[FromDigits[Reverse[IntegerDigits[i]]], {i, t}]; Intersection[t, tr] (* _T. D. Noe_, Mar 16 2013 *)

%Y Cf. A000959, A309406.

%K base,nonn

%O 1,2

%A Luc Stevens (lms022(AT)yahoo.com), May 07 2006

%E Corrected and extended by Adam Panagos (adam.panagos(AT)gmail.com), May 10 2006

%E 957 removed by _T. D. Noe_, Mar 16 2013

Lookup | Welcome | Wiki | Register | Music | Plot 2 | Demos | Index | Browse | More | WebCam
Contribute new seq. or comment | Format | Style Sheet | Transforms | Superseeker | Recents
The OEIS Community | Maintained by The OEIS Foundation Inc.

License Agreements, Terms of Use, Privacy Policy. .

Last modified July 21 22:18 EDT 2024. Contains 374477 sequences. (Running on oeis4.)