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 A348688 #15 Nov 02 2021 22:25:14
%S A348688 1,8,5,17,11,22,18,34,15,44,30,42,31,61,34,68,35,69,58,86,32,89,73,93,
%T A348688 57,108,54,126,71,119,89,117,59,155,117,133,64,164,92,184,98,146,134,
%U A348688 186,74,187,136,202,124,209,104,200,126,232,182,230,62,256,194,222,135,243,171,287,170
%N A348688 a(n) = sigma(n) + sigma(n+1) + sigma(n+2) - sigma(n+3), where sigma is the sum of divisors.
%H A348688 Michel Marcus, <a href="/A348688/b348688.txt">Table of n, a(n) for n = 1..11000</a>
%t A348688 Array[#+#2+#3-#4&@@DivisorSigma[1,{#,#+1,#+2,#+3}]&,100] (* _Giorgos Kalogeropoulos_, Oct 29 2021 *)
%o A348688 (PARI) a(n) = sigma(n) + sigma(n+1) + sigma(n+2) - sigma(n+3);
%Y A348688 Cf. A000203, A348335, A348689, A348698 (a(n) <= 0).
%K A348688 sign
%O A348688 1,2
%A A348688 _Michel Marcus_, Oct 29 2021