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 A071326 #14 May 15 2025 00:50:29
%S A071326 0,0,0,4,0,0,0,4,9,0,0,4,0,0,0,20,0,9,0,4,0,0,0,4,25,0,9,4,0,0,0,20,0,
%T A071326 0,0,49,0,0,0,4,0,0,0,4,9,0,0,20,49,25,0,4,0,9,0,4,0,0,0,4,0,0,9,84,0,
%U A071326 0,0,4,0,0,0,49,0,0,25,4,0,0,0,20,90,0,0,4,0,0,0,4,0,9,0,4,0,0,0,20,0,49,9,129
%N A071326 Sum of squares > 1 dividing n.
%H A071326 Antti Karttunen, <a href="/A071326/b071326.txt">Table of n, a(n) for n = 1..16384</a>
%F A071326 a(n) = A035316(n)-1.
%F A071326 Sum_{d|n, d>1} A010052(d). - _Antti Karttunen_, Nov 17 2017
%t A071326 Array[DivisorSum[#, # &, IntegerQ@ Sqrt@ # &] - 1 &, 100] (* _Michael De Vlieger_, Nov 17 2017 *)
%t A071326 f[p_, e_] := (p^(2*(1+Floor[e/2]))-1)/(p^2-1); a[1] = 0; a[n_] := Times @@ f @@@ FactorInteger[n] - 1; Array[a, 100] (* _Amiram Eldar_, May 15 2025 *)
%o A071326 (PARI) A071326(n) = sumdiv(n,d,(d>1)*issquare(d)*d); \\ _Antti Karttunen_, Nov 17 2017
%Y A071326 Cf. A000203, A010052, A071325, A071327.
%Y A071326 One less than A035316.
%K A071326 nonn
%O A071326 1,4
%A A071326 _Reinhard Zumkeller_, May 18 2002
%E A071326 More terms from _Antti Karttunen_, Nov 17 2017