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 A109051 #28 Nov 26 2022 04:03:01
%S A109051 0,10,10,30,20,10,30,70,40,90,10,110,60,130,70,30,80,170,90,190,20,
%T A109051 210,110,230,120,50,130,270,140,290,30,310,160,330,170,70,180,370,190,
%U A109051 390,40,410,210,430,220,90,230,470,240,490,50,510,260,530,270,110,280
%N A109051 a(n) = lcm(n,10).
%H A109051 Amiram Eldar, <a href="/A109051/b109051.txt">Table of n, a(n) for n = 0..10000</a>
%H A109051 <a href="/index/Rec#order_20">Index entries for linear recurrences with constant coefficients</a>, signature (0,0,0,0,0,0,0,0,0,2,0,0,0,0,0,0,0,0,0,-1).
%H A109051 <a href="/index/Lc#lcm">Index entries for sequences related to lcm's</a>.
%F A109051 a(n) = n*10/gcd(n, 10).
%F A109051 a(n) = 10*n/A109013(n) = 10*A106611(n). - _R. J. Mathar_, Apr 18 2011
%F A109051 G.f.: 10*x*(1 +x +3*x^2 +2*x^3 +x^4 +3*x^5 +7*x^6 +4*x^7 +9*x^8 +x^9 +9*x^10 +4*x^11 +7*x^12 +3*x^13 +x^14 +2*x^15 +3*x^16 +x^17 +x^18)/(1 -x^10)^2. - _Robert Israel_, Feb 23 2016
%F A109051 Sum_{k=1..n} a(k) ~ (63/20) * n^2. - _Amiram Eldar_, Nov 26 2022
%p A109051 q:= [seq(10/igcd(i,10),i=1..10)]:
%p A109051 [0,seq(seq((10*i+j)*q[j],j=1..10),i=0..10)]; # _Robert Israel_, Feb 23 2016
%t A109051 a[n_] := LCM[n, 10]; Array[a, 60, 0] (* _Amiram Eldar_, Nov 26 2022 *)
%o A109051 (Sage) [lcm(n,10)for n in range(0, 57)] # _Zerinvary Lajos_, Jun 07 2009
%o A109051 (Magma) [Lcm(n,10): n in [0..100]]; // _Vincenzo Librandi_, Apr 18 2011
%o A109051 (PARI) a(n) = lcm(n, 10); \\ _Michel Marcus_, Feb 23 2016
%Y A109051 Cf. A106611, A109013, A109042.
%K A109051 nonn,easy
%O A109051 0,2
%A A109051 _Mitch Harris_, Jun 18 2005