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 A087009 #28 Mar 15 2024 07:24:54
%S A087009 1,0,2,4,6,12,24,48,96,192,384,768,1536,3072,6144,12288,24576,49152,
%T A087009 98304,196608,393216,786432,1572864,3145728,6291456,12582912,25165824,
%U A087009 50331648,100663296,201326592,402653184,805306368,1610612736,3221225472
%N A087009 Least m such that omega(m) + Omega(m) = n, or 0 if no such m exists.
%H A087009 <a href="/index/Rec#order_01">Index entries for linear recurrences with constant coefficients</a>, signature (2).
%F A087009 For n > 3, a(n) = 2^(n-3)*3. - _Ray Chandler_, Nov 01 2003
%F A087009 a(n) = A058764(n-2). - _Philippe Deléham_, Oct 17 2011
%F A087009 G.f.: (2*x^4-2*x^2+2*x-1)/(2*x-1). - _Colin Barker_, Oct 23 2012
%t A087009 Join[{1, 0, 2, 4}, LinearRecurrence[{2}, {6}, 40]] (* _Jean-François Alcover_, Mar 07 2020 *)
%o A087009 (PARI) a(n) = {m = 1; while (omega(m) + bigomega(m) != n, m++); m} \\ _Michel Marcus_, Oct 23 2013
%Y A087009 First occurrence of n in A080256.
%K A087009 nonn,easy
%O A087009 0,3
%A A087009 _Lekraj Beedassy_, Oct 13 2003
%E A087009 Corrected and extended by _Ray Chandler_, Nov 01 2003