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 A226475 #23 Jul 23 2015 16:07:46
%S A226475 75,113,295,533,686,2130,14805,26966,30235,35095,135653,355675,432996,
%T A226475 590138,1214588,2692853,2952064,3375195,3486795,5973014,6880351,
%U A226475 7334956,22266602,25841659,30483834,37416582,38390010,40952513,41109593,57242145
%N A226475 Numbers n such that sigma(n) + sigma(n+1) = sigma(n+2) + sigma(n+3).
%C A226475 Sigma(n) is the sum of the divisors of n: A000203.
%H A226475 Giovanni Resta, <a href="/A226475/b226475.txt">Table of n, a(n) for n = 1..138</a> (terms < 10^13)
%e A226475 sigma(75) + sigma(76) = 124 + 140 = 264, and sigma(77) + sigma(78) = 96 + 168 = 264, so 75 is in the sequence.
%t A226475 t = {}; s = DivisorSigma[1, Range[0, 3]]; n = 3; While[Length[t] < 10, n++; s = RotateLeft[s]; s[[4]] = DivisorSigma[1, n]; If[s[[1]] + s[[2]] == s[[3]] + s[[4]], AppendTo[t, n - 3]]]; t (* _T. D. Noe_, Jun 12 2013 *)
%t A226475 Module[{ds=DivisorSigma[1,Range[6*10^7]]},Flatten[Position[Partition[ds,4,1],_?(Total[Take[#,2]]==Total[Take[#,-2]]&),{1},Heads->False]]] (* _Harvey P. Dale_, Sep 13 2014 *)
%Y A226475 Cf. A000203, A055574, A065900, A073500, A099632, A226361.
%K A226475 nonn
%O A226475 1,1
%A A226475 _Alex Ratushnyak_, Jun 11 2013