%I #3 May 31 2021 18:17:16

%S 1,3,4,8,7,13,9,18,15,22,14,35,16,28,29,40,21,49,23,58,38,43,27,80,40,

%T 50,50,75,34,97,36,85,58,64,64,131,43,71,67,132,47,126,49,114,108,83,

%U 53,178,70,127,87,133,60,164,99,171,95,104,66,258,68,110,142,178,114,191,75

%N a(n) = n * Sum_{d|n} floor(sqrt(d)) / d.

%e a(6) = 6 * Sum_{d|6} floor(sqrt(d)) / d = 6 * (floor(sqrt(1))/1 + floor(sqrt(2))/2 + floor(sqrt(3))/3 + floor(sqrt(6))/6) = 6 * (1 + 1/2 + 1/3 + 2/6) = 13.

%t Table[n*Sum[Floor[Sqrt[k]] (1 - Ceiling[n/k] + Floor[n/k])/k, {k, n}], {n, 100}]

%Y Cf. A344460.

%K nonn

%O 1,2

%A _Wesley Ivan Hurt_, May 31 2021