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 A110177 #7 Feb 20 2023 12:26:33
%S A110177 0,0,2,0,0,0,0,2,2,2,0,0,0,0,2,0,0,0,0,2,2,0,0,0,0,0,0,0,0,2,0,4,2,0,
%T A110177 0,0,0,0,2,2,0,0,0,0,0,0,0,0,2,0,2,0,0,0,4,2,4,0,0,0,0,2,4,0,0,0,0,0,
%U A110177 4,2,0,0,0,0,2,0,0,0,0,0,0,0,0,0,2,0,4,2,0,2,0,2,2,2,0,2,0,0,2,0,0,0,0,2,4
%N A110177 Number of solutions 0<k<n to the equation sigma(n) = sigma(k) + sigma(n-k), where sigma is the sum of divisors function.
%C A110177 The number of solutions is always even because k=n/2 cannot be a solution for even n.
%H A110177 Antti Karttunen, <a href="/A110177/b110177.txt">Table of n, a(n) for n = 1..16384</a>
%t A110177 a[n_] := Select[Range[n-1], DivisorSigma[1, n]==DivisorSigma[1, n-# ]+DivisorSigma[1, # ]&]; Table[Length[a[n]], {n, 150}]
%o A110177 (PARI) A110177(n) = { my(x=sigma(n)); sum(k=1,n-1,(x == (sigma(k)+sigma(n-k)))); }; \\ _Antti Karttunen_, Feb 20 2023
%Y A110177 Cf. A110176 (least k such that sigma(n)=sigma(k)+sigma(n-k)).
%Y A110177 Cf. also A110174.
%K A110177 nonn
%O A110177 1,3
%A A110177 _T. D. Noe_, Jul 15 2005