%I A153818
%S A153818 1,5,12,22,35,53,72,96,123,153,184,222,260,304,351,402,453,510,568,633,
%T A153818 697,765,839,916,994,1077,1164,1252,1342,1443,1535,1641,1747,1856,1969,
%U A153818 2083,2200,2321,2447,2579,2705,2844,2979,3123,3269,3417,3570,3726,3881
%N A153818 a(n)=Sum_{k=1..n} floor(n^2/k^2)
%C A153818 How to express Sum_{k=1..n} floor(n^2/k^2) as a function of Sum_{k=1..n} 
               floor(n/k) ? [From Ctibor O. Zizka (c.zizka(AT)email.cz), Feb 14 
               2009]
%e A153818 a(4)=22 because floor(16/1)+floor(16/4)+floor(16/9)+floor(16,16)=16+4+1+1=22. 
               [From Emeric Deutsch (deutsch(AT)duke.poly.edu), Jan 13 2009]
%p A153818 a := proc (n) options operator, arrow: sum(floor(n^2/k^2), k = 1 .. n) 
               end proc: seq(a(n), n = 1 .. 50); [From Emeric Deutsch (deutsch(AT)duke.poly.edu), 
               Jan 13 2009]
%Y A153818 Cf. A006218
%Y A153818 Sequence in context: A000326 A022795 A025734 this_sequence A069627 A034971 
               A025740
%Y A153818 Adjacent sequences: A153815 A153816 A153817 this_sequence A153819 A153820 
               A153821
%K A153818 easy,nonn
%O A153818 1,2
%A A153818 Ctibor O. Zizka (c.zizka(AT)email.cz), Jan 02 2009
%E A153818 Definition edited by Emeric Deutsch (deutsch(AT)duke.poly.edu), Jan 13 
               2009
%E A153818 Extended by Emeric Deutsch (deutsch(AT)duke.poly.edu), Jan 13 2009