Logo

Greetings from The On-Line Encyclopedia of Integer Sequences!

Hints

Search: id:A128921
Displaying 1-1 of 1 results found. page 1
     Format: long | short | internal | text      Sort: relevance | references | number      Highlight: on | off
%I A128921
%S A128921 0,1,2,3,11,22,33,99,101,111,121,202,212,1001,1111,2002,10001,10101,
%T A128921 10201,11011,11111,11211,20002,20102,100001,101101,110011,111111,200002,
%U A128921 1000001,1001001,1002001,1010101,1011101,1012101,1100011,1101011
%N A128921 Palindromes p such that reverse of p^2 is also a square.
%C A128921 Most terms have a palindromic square; for the rare exceptions see A133901. 
               (Klaus Brockhaus and Zak Seidov, Sep 29 2007)
%H A128921 Klaus Brockhaus, <a href="b128921.txt">Table of n, a(n) for n = 1..360</
               a>
%e A128921 33 and 99 are terms because 33^2=1089 => 9801=99^2 and 99^2=9801 => 1089=33^2.
%t A128921 A128921=Select[Range[0, 100000], IntegerQ[Sqrt[FromDigits[Reverse[IntegerDigits[ 
               #^2 ]]]]]&&FromDigits[Reverse[IntegerDigits[ # ]]]==#&]
%Y A128921 Cf. A002113, A057135, A057136, A133901.
%Y A128921 Sequence in context: A049083 A002778 A028816 this_sequence A118595 A057135 
               A104075
%Y A128921 Adjacent sequences: A128918 A128919 A128920 this_sequence A128922 A128923 
               A128924
%K A128921 easy,nonn,base
%O A128921 1,3
%A A128921 Zak Seidov (zakseidov(AT)yahoo.com), Mar 02 2005, definition corrected 
               Sep 16 2007
%E A128921 More terms from Klaus Brockhaus (klaus-brockhaus(AT)t-online.de), Sep 
               23 2007

    
page 1

Search completed in 0.002 seconds

Lookup | Welcome | Find friends | Music | Plot 2 | Demos | Index | Browse | More | WebCam
Contribute new seq. or comment | Format | Transforms | Puzzles | Hot | Classics
More pages | Superseeker | Maintained by N. J. A. Sloane (njas@research.att.com)

Last modified December 21 10:15 EST 2009. Contains 171081 sequences.


AT&T Labs Research