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 A112773 #24 Feb 20 2017 00:26:31
%S A112773 3,6,9,15,21,33,39,51,57,69,87,93,111,123,129,141,159,177,183,201,213,
%T A112773 219,237,249,267,291,303,309,321,327,339,381,393,411,417,447,453,471,
%U A112773 489,501,519,537,543,573,579,591,597,633,669,681,687,699,717,723,753
%N A112773 3 together with primes multiplied by 3.
%C A112773 3 times the noncomposite numbers (see formula). Also column 2 of A272400. - _Omar E. Pol_, Apr 29 2016
%H A112773 G. C. Greubel, <a href="/A112773/b112773.txt">Table of n, a(n) for n = 1..1000</a>
%F A112773 a(n) = 3*A008578(n). - _Omar E. Pol_, Jan 31 2012
%t A112773 Insert[Table[3Prime[n], {n, 1, 60}], 3, 1] (* _Stefan Steinerberger_, Mar 30 2006 *)
%Y A112773 Essentially the same as A001748.
%Y A112773 Cf. A000040, A001747, A008578, A008585, A046315.
%K A112773 easy,nonn
%O A112773 1,1
%A A112773 _Jonathan Vos Post_ and _Ray Chandler_, Oct 15 2005
%E A112773 Edited by _N. J. A. Sloane_, Apr 28 2008 at the suggestion of _Alexander R. Povolotsky_