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 A369516 #19 Jan 30 2025 19:17:14
%S A369516 12,18,20,24,28,36,40,48,50,52,54,56,60,63,68,72,80,84,88,90,92,96,
%T A369516 104,108,112,120,124,126,132,140,144,150,156,160,162,164,168,180,184,
%U A369516 192,196,198,200,204,212,216,220,228,232,234,236,240,242,248,250,252,264
%N A369516 Numbers k in A126706 such that neither k-1 nor k+1 is in A126706.
%C A369516 Singletons in A126706.
%C A369516 The smallest odd term is 63.
%C A369516 Terms are even or divisible by 3, or both. Does not include k coprime to 6; k in A369954 are not in this sequence.
%H A369516 Michael De Vlieger, <a href="/A369516/b369516.txt">Table of n, a(n) for n = 1..10000</a>
%e A369516 Define quality Q to signify a number k neither squarefree nor prime power, i.e., k is in A126706. For example, 12 has quality Q but k = 1..11 do not.
%e A369516 The number 12 is in the sequence since it has quality Q, but neither 11 nor 13 do.
%e A369516 The number 44 is not in the sequence since 45 has quality Q.
%e A369516 The number 99 is not in the sequence because both 98 and 100 have quality Q, etc.
%t A369516 Select[Select[Range[264], Nor[SquareFreeQ[#], PrimePowerQ[#]] &], NoneTrue[{# - 1, # + 1}, Nor[SquareFreeQ[#], PrimePowerQ[#]] &] &]
%t A369516 Mean/@SequencePosition[Table[If[!SquareFreeQ[n]&&!PrimePowerQ[n],1,0],{n,300}],{0,1,0}] (* _Harvey P. Dale_, Jan 30 2025 *)
%Y A369516 Cf. A126706, A369276, A369954.
%K A369516 nonn,easy
%O A369516 1,1
%A A369516 _Michael De Vlieger_, Mar 24 2024