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 A356742 #10 Oct 07 2022 11:56:53
%S A356742 6,8,33,55,85,91,93,123,141,143,159,183,185,201,203,213,215,217,219,
%T A356742 235,247,265,299,301,303,319,321,327,339,341,391,393,411,413,415,445,
%U A356742 451,469,471,515,517,533,535,543,551,579,581,589,633,667,669,679,685,687,695,697
%N A356742 Numbers k such that k and k+2 both have exactly 4 divisors.
%C A356742 6 and 8 are the only even terms: one of the two consecutive even numbers is divisible by 4, and the only multiple of 4 with exactly 4 divisors is 8.
%H A356742 Jianing Song, <a href="/A356742/b356742.txt">Table of n, a(n) for n = 1..10000</a>
%e A356742 341 is a term since 341 and 343 both have 4 divisors.
%t A356742 SequencePosition[DivisorSigma[0,Range[700]],{4,_,4}][[All,1]] (* _Harvey P. Dale_, Oct 07 2022 *)
%o A356742 (PARI) isA356742(n) = numdiv(n)==4 && numdiv(n+2)==4
%Y A356742 Numbers k such that k and k+2 both have exactly m divisors: A001359 (m=2), this sequence (m=4), A356743 (m=6), A356744 (m=8).
%Y A356742 Cf. also A039832 (numbers k such that k and k+1 both have exactly 4 divisors).
%K A356742 nonn
%O A356742 1,1
%A A356742 _Jianing Song_, Aug 25 2022