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 A076752 #40 Aug 20 2021 00:21:38
%S A076752 1,2,3,5,5,6,7,10,10,10,11,15,13,14,15,21,17,20,19,25,21,22,23,30,26,
%T A076752 26,30,35,29,30,31,42,33,34,35,50,37,38,39,50,41,42,43,55,50,46,47,63,
%U A076752 50,52,51,65,53,60,55,70,57,58,59,75,61,62,70,85,65,66,67,85,69,70,71
%N A076752 a(n) = Sum_{d is a square divisor of n} n/d.
%C A076752 The Mobius transform of this sequence appears to generate the sequence of absolute terms of A061020. - _R. J. Mathar_, Feb 08 2011
%H A076752 Ivan Neretin, <a href="/A076752/b076752.txt">Table of n, a(n) for n = 1..10000</a>
%F A076752 Multiplicative with a(p^e) = (p^(e+2)-1)/(p^2-1) for even e and a(p^e) = p*(p^(e+1)-1)/(p^2-1) for odd e.
%F A076752 a(p ^ (m + 1)) = p * a(p^m) for even m and a(p ^ (m + 1)) = p * a(p^m) + 1 for odd m. - _David A. Corneth_, Nov 03 2017
%F A076752 a(n) = (lambda * sigma)(n) = (A008836 * A000203)(n), where * is the Dirichlet convolution. - _Yuyang Zhao_, Nov 02 2017
%F A076752 From _Vaclav Kotesovec_, Feb 04 2019: (Start)
%F A076752 Dirichlet g.f.: zeta(2*s)*zeta(s-1).
%F A076752 Sum_{k=1..n} a(k) ~ Pi^4 * n^2 / 180. (End)
%F A076752 G.f.: Sum_{k>=1} x^(k^2) / (1 - x^(k^2))^2. - _Ilya Gutkovskiy_, Aug 19 2021
%e A076752 a(8) = 10 as the square divisors of 8 are 1 and 4, and 8/1 + 8/4 = 10. - _David A. Corneth_, Nov 03 2017
%t A076752 Table[Total[n/Select[Divisors[n], IntegerQ@Sqrt@# &]], {n, 71}] (* _Ivan Neretin_, Sep 20 2017 *)
%t A076752 Table[DivisorSum[n, n/# &, IntegerQ@ Sqrt@ # &], {n, 71}] (* _Michael De Vlieger_, Nov 03 2017 *)
%t A076752 f[p_, e_] := p^(k = If[EvenQ[e], 0, 1])*(p^(e + 2 - k) - 1)/(p^2 - 1); a[1] = 1; a[n_] := Times @@ f @@@ FactorInteger[n]; Array[a, 100] (* _Amiram Eldar_, May 01 2020 *)
%o A076752 (PARI) a(n,f=factor(n))=prod(i=1,#f~, if(f[i,2]%2, f[i,1]*(f[i,1]^(f[i,2]+1)-1), (f[i,1]^(f[i,2]+2)-1))/(f[i,1]^2-1)) \\ _Charles R Greathouse IV_, Sep 20 2017
%o A076752 (PARI) a(n) = sumdiv(n, d, (n/d)*issquare(d)); \\ _Michel Marcus_, Nov 02 2017
%Y A076752 Cf. A000203, A008836, A035316.
%K A076752 mult,nonn
%O A076752 1,2
%A A076752 _Vladeta Jovovic_, Nov 12 2002