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 A048969 #25 Nov 01 2023 08:54:49
%S A048969 6,20,45,49,150,169,361,832,961,1445,1734,1849,5329,8405,9409,9477,
%T A048969 10086,10609,14580,14641,16129,17405,20886,24649,25205,30246,39601,
%U A048969 39605,47526,49729,51005,58081,61206,73441,85805,102966,139445,149645,167281,167334
%N A048969 Composite numbers k such that sigma(k) / d(k) is prime.
%H A048969 Donovan Johnson, <a href="/A048969/b048969.txt">Table of n, a(n) for n = 1..1000</a> (first 259 terms from T. D. Noe)
%e A048969 For k=6 (composite), sigma(6)=12, d(6)=4 and 12/4 = 3 is prime.
%t A048969 nn=62000;With[{comps=Complement[Range[nn],Prime[Range[PrimePi[nn]]]]}, Select[ comps, PrimeQ[DivisorSigma[1,#]/DivisorSigma[0,#]]&]] (* _Harvey P. Dale_, Feb 19 2012 *)
%Y A048969 Cf. A000203, A000005, A000043, A048968.
%K A048969 nice,easy,nonn
%O A048969 1,1
%A A048969 _G. L. Honaker, Jr._
%E A048969 More terms from _Michel ten Voorde_