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Search: id:A050250
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%I A050250
%S A050250 9,18,108,198,1098,1998,10998,19998,109998,199998,1099998,1999998,
%T A050250 10999998,19999998,109999998,199999998,1099999998,1999999998,
%U A050250 10999999998,19999999998,109999999998,199999999998,1099999999998,1999999999998,
               10999999999998
%N A050250 Number of nonzero palindromes less than 10^n.
%H A050250 Dr. Math, <a href="http://mathforum.org/dr.math/problems/stang4.8.14.97.html">
               More info 1</a>
%H A050250 Dr. Math, <a href="http://mathforum.org/dr.math/problems/akyildiz1.4.98.html">
               More info 2</a>
%H A050250 Eric Weisstein's World of Mathematics, <a href="http://mathworld.wolfram.com/
               PalindromicNumber.html">Link to a section of The World of Mathematics.</
               a>
%F A050250 a(2n)=2*10^n-2, a(2n+1)=11*10^n-2 - Sascha Kurz (sascha.kurz(AT)uni-bayreuth.de), 
               Apr 14 2002
%F A050250 a(n) = Partial sum of A050683 = SUM[i=1..n] A050683(i) = SUM[i=1..n] 
               9*10^floor[(i-1)/2] = 9 * SUM[i=1..n] 10^floor[(i-1)/2]. - a(24)-a(25) 
               from Jonathan Vos Post (jvospost3(AT)gmail.com), Jun 18 2008
%Y A050250 Cf. A002113, A050683. Differences give A050683.
%Y A050250 Cf. A050683.
%Y A050250 Sequence in context: A140149 A066711 A033651 this_sequence A080453 A002169 
               A050685
%Y A050250 Adjacent sequences: A050247 A050248 A050249 this_sequence A050251 A050252 
               A050253
%K A050250 nonn,easy,base,nice
%O A050250 1,1
%A A050250 Eric Weisstein (eric(AT)weisstein.com)
%E A050250 More terms from Patrick De Geest (pdg(AT)worldofnumbers.com), 8/99.
%E A050250 a(24)-a(25) from Jonathan Vos Post (jvospost3(AT)gmail.com), Jun 18 2008

    
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Last modified December 11 12:57 EST 2009. Contains 170656 sequences.


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