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 A067130 #17 May 25 2024 20:05:44
%S A067130 2,34,55,119,285,367,835,849,919,1241,1505,1559,2911,2914,2939,3305,
%T A067130 4149,4188,6111,6903,7170,7913,9360,10251,10541,12566,15086,17273,
%U A067130 17759,17815,19005,19689,19919,21411,21462,24882,25020,26610,28125,30593,30789,31485
%N A067130 Numbers k such that sigma(k-1) divides sigma(k+1).
%H A067130 Donovan Johnson, <a href="/A067130/b067130.txt">Table of n, a(n) for n = 1..1000</a>
%t A067130 Flatten[Position[Partition[DivisorSigma[1,Range[32000]],3,1],_?( Divisible[ Last[#],First[#]]&),{1},Heads->False]]+1 (* _Harvey P. Dale_, Jan 13 2015 *)
%o A067130 (PARI) isok(n) = sigma(n+1) % sigma(n-1) == 0; \\ _Michel Marcus_, Nov 20 2013
%Y A067130 Cf. A000203 (sigma), A055574.
%K A067130 nonn
%O A067130 1,1
%A A067130 _Benoit Cloitre_, Feb 18 2002
%E A067130 More terms from _Michel Marcus_, Nov 20 2013