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 A258468 #15 Mar 04 2018 09:38:32
%S A258468 0,0,3,4,15,6,35,8,18,30,99,12,143,70,165,176,255,36,323,140,357,198,
%T A258468 483,48,550,286,621,308,783,330,899,416,957,510,1085,108,1295,646,
%U A258468 1365,160,1599,714,1763,836,585,966,2115,912,2254,1100,2397,1196
%N A258468 a(n) = lcm(n, n - tau(n)).
%C A258468 For tau see A000005.
%H A258468 Joshua Zelinsky, <a href="https://cs.uwaterloo.ca/journals/JIS/VOL5/Zelinsky/zelinsky9.html">Tau Numbers: A Partial Proof of a Conjecture and Other Results</a>, Journal of Integer Sequences, Vol. 5 (2002), Article 02.2.8.
%F A258468 a(n) = lcm(n, n - tau(n)).
%F A258468 a(n) = n * (n - 2) = A005563(n-2) if n is prime.
%e A258468 a(5) = 15, since tau(5) = 2, lcm(5, 3) = 15.
%e A258468 a(7) = 35, since tau(7) = 2, lcm(7, 5) = 35.
%e A258468 a(10) = 30, since tau(10) = 4, lcm (10, 6) = 30.
%t A258468 Table[LCM[n, n - DivisorSigma[0, n]], {n, 200}]
%o A258468 (PARI) vector(100, n, lcm(n, n-numdiv(n))) \\ _Michel Marcus_, May 31 2015
%Y A258468 Cf. A000005, A009230, A005563.
%K A258468 nonn,easy
%O A258468 1,3
%A A258468 _Carlos Eduardo Olivieri_, May 31 2015
%E A258468 Edited by _Wolfdieter Lang_, Jun 16 2015