This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.
%I A344405 #7 May 17 2021 17:56:08
%S A344405 1,4,9,18,25,39,49,72,84,110,121,166,169,217,230,292,289,372,361,455,
%T A344405 455,539,529,670,630,754,756,889,841,1041,961,1168,1122,1292,1232,
%U A344405 1530,1369,1615,1573,1828,1681,2037,1849,2200,2109,2369,2209,2716,2408,2820,2686
%N A344405 a(n) = Sum_{d|n} (n/d) * floor(n/d^2).
%C A344405 If p is prime, a(p) = Sum_{d|p} (p/d) * floor(p/d^2) = p*p + 1*0 = p^2.
%e A344405 a(4) = 18; Sum_{d|4} (4/d) * floor(4/d^2) = 4*4 + 2*1 + 1*0 = 18.
%t A344405 Table[Sum[(1 - Ceiling[n/k] + Floor[n/k]) (n/k) Floor[n/k^2], {k, n}], {n, 100}]
%o A344405 (PARI) a(n) = sumdiv(n, d, (n/d)*(n\d^2)); \\ _Michel Marcus_, May 17 2021
%Y A344405 Cf. A344128, A344403, A344404.
%K A344405 nonn
%O A344405 1,2
%A A344405 _Wesley Ivan Hurt_, May 16 2021