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 A065745 #19 Dec 15 2023 06:19:16
%S A065745 1,3,1,7,1,3,1,15,10,3,1,7,1,3,1,31,1,30,1,7,1,3,1,15,26,3,10,7,1,3,1,
%T A065745 63,1,3,1,70,1,3,1,15,1,3,1,7,10,3,1,31,50,78,1,7,1,30,1,15,1,3,1,7,1,
%U A065745 3,10,127,1,3,1,7,1,3,1,150,1,3,26,7,1,3,1,31,91,3,1,7,1,3,1,15,1,30,1
%N A065745 Sum of squares and twice squares dividing n.
%H A065745 Antti Karttunen, <a href="/A065745/b065745.txt">Table of n, a(n) for n = 1..65537</a>
%F A065745 Multiplicative with a(2^e) = 2^(e+1)-1, a(p^e) = (p^(e+2)-1)/(p-1)/(p+1) for odd p and even e and a(p^e) = (p^(e+1)-1)/(p-1)/(p+1) for odd p and odd e.
%F A065745 From _Amiram Eldar_, Dec 15 2023: (Start)
%F A065745 Dirichlet g.f.: (1 + 1/2^(s-1)) * zeta(2*s-2) * zeta(s).
%F A065745 Sum_{k=1..n} a(k) ~ c * n^(3/2), where c = ((2+sqrt(2))/6) * zeta(3/2) = 1.4865345575818562471... . (End)
%t A065745 f[2, e_] := 2^(e+1) - 1; f[p_, e_] := If[OddQ[e], (p^(e+1)-1)/(p^2-1), (p^(e+2)-1)/(p^2-1)]; a[1] = 1; a[n_] := Times @@ f @@@ FactorInteger[n]; Array[a, 100] (* _Amiram Eldar_, Sep 13 2020 *)
%o A065745 (PARI) a(n) = sumdiv(n, d, issquare(d)*d + (1 - d%2)*issquare(d/2)*d) \\ _Michel Marcus_, Jun 17 2013
%Y A065745 Cf. A035316, A065704, A078434.
%K A065745 mult,nonn,easy
%O A065745 1,2
%A A065745 _Vladeta Jovovic_, Dec 04 2001
%E A065745 More terms from _Matthew Conroy_, Jan 19 2002