A330476 a(n) = Sum_{m=2..n} floor(n/m)^2.

0, 1, 2, 6, 7, 16, 17, 28, 34, 47, 48, 75, 76, 93, 108, 134, 135, 172, 173, 212, 231, 256, 257, 322, 332, 361, 384, 435, 436, 513, 514, 571, 598, 635, 658, 760, 761, 802, 833, 926, 927, 1028, 1029, 1104, 1165, 1214, 1215, 1358, 1372, 1453, 1492, 1579, 1580, 1705, 1736, 1857, 1900, 1961, 1962

Offset: 1

Author

Robert Israel, Dec 15 2019

Keywords

• nonn

Examples

			a(4) = floor(4/2)^2 + floor(4/3)^2 + floor(4/4)^2 = 6.
		

Links

• Robert Israel, Table of n, a(n) for n = 1..5000

Crossrefs

Cf. A002541, A224526.

Programs

Magma

[0] cat [&+[Floor(n/m)^2:m in [2..n]]:n in [2..60]]; // Marius A. Burtea, Dec 15 2019

Maple

f:=  proc(n) local m; add(floor(n/m)^2,m=2..n) end proc:
map(f, [$1..100]);

Mathematica

Table[Sum[IntegerPart[(n/m)]^2,{m,2,n}],{n,1,100}] (* Metin Sariyar, Dec 15 2019 *)