Search: id:A030485
Results 1-1 of 1 results found.

%I A030485
%S A030485 25,225,7225,27225,55225,2772225,227557225,277722225,27777222225,
%T A030485 72272257225,2777772222225,25772527522225,277777722222225,
%U A030485 2775552752755225,27522257555772225,27777777222222225,77525222275255225
%N A030485 Squares composed of digits {2,5,7}.
%C A030485 We can easily prove that except for the first term all terms are of the 
               form 100*m^2+100*m+25 where mod(m, 10) is one of the numbers 1, 3, 
               6 & 8. Also we can show that all numbers of the form ((5*10^n-5)/
               3)^2 where n is a natural number, are in the sequence. [From Farideh 
               Firoozbakht (mymontain(AT)yahoo.com), Dec 09 2008]
%H A030485 P. De Geest, <a href="http://www.worldofnumbers.com/threedigits.htm">
               Squares containing at most three distinct digits, Index entries for 
               related sequences</a>
%Y A030485 Cf. A030487.
%Y A030485 Sequence in context: A067472 A058426 A048384 this_sequence A036509 A034981 
               A053919
%Y A030485 Adjacent sequences: A030482 A030483 A030484 this_sequence A030486 A030487 
               A030488
%K A030485 nonn,base
%O A030485 1,1
%A A030485 Patrick De Geest (pdg(AT)worldofnumbers.com)
%E A030485 Extended and corrected by author 03/2000.
%E A030485 a(17)-a(19) from Farideh Firoozbakht (mymontain(AT)yahoo.com), Dec 09 
               2008

Search completed in 0.003 seconds