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 A168630 #11 May 09 2018 16:54:42 %S A168630 46189,50634,69597,76797,90117,97954,108205,115804,127347,138957, %T A168630 144627,159340,164020,166022,166497,166705,167205,167485,173194, %U A168630 174454,181670,186294,190014,193154,198789,211029,212134,214225,217217,221815,222547,224146 %N A168630 Numbers n such that n, n+1, and the sum of those two numbers each have 4 or more distinct prime factors. %H A168630 Robert Israel, <a href="/A168630/b168630.txt">Table of n, a(n) for n = 1..10000</a> %e A168630 FactorInteger[46189]=11*13*17*19, FactorInteger[46190]=2*5*31*149, FactorInteger[46189+46190]=3*7*53*83,.. %p A168630 g:= proc(n) option remember; nops(numtheory:-factorset(n))>=4 end proc: %p A168630 filter:= n -> g(n) and g(n+1) and g(2*n+1): %p A168630 select(filter, [$1..300000]); # _Robert Israel_, May 09 2018 %t A168630 f[n_]:=Length[FactorInteger[n]]; lst={};Do[If[f[n]>=4&&f[n+1]>=4&&f[n+n+1]>=4,AppendTo[lst,n]],{n,9!}];lst %t A168630 Select[Range[225000],Min[Thread[PrimeNu[{#,#+1,2#+1}]]]>3&](* _Harvey P. Dale_, Nov 11 2017 *) %Y A168630 Cf. A140077, A140078, A168626, A168628, A168629 %K A168630 nonn %O A168630 1,1 %A A168630 _Vladimir Joseph Stephan Orlovsky_, Dec 01 2009 %E A168630 Definition modified and terms extended by _Harvey P. Dale_, Nov 11 2017