Search: id:A153818 Results 1-1 of 1 results found. %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 Search completed in 0.001 seconds