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 A193181 #39 Oct 19 2018 03:28:54 %S A193181 2,10,10,170,2210,81770,408850,408850,16762850,1693047850, %T A193181 103275918850,2995001646650,2995001646650,590015324390050, %U A193181 66671731656075650,17134635035611442050,17134635035611442050,17134635035611442050,3101368941445671011050 %N A193181 a(n) = lcm(f(1),f(2),...,f(n)) with f(x) = x^2+1. %C A193181 log(a(n)) = n*log(n)+B*n+o(n); B=-0.066275634213060706383563177025. %C A193181 All prime factors of a(n) are in A002313. - _Robert Israel_, Mar 13 2016 %H A193181 Robert Israel, <a href="/A193181/b193181.txt">Table of n, a(n) for n = 1..388</a> %H A193181 J. Cilleruelo, <a href="http://arxiv.org/abs/1001.3438">The least common multiple of a quadratic sequence</a>, arXiv:1001.3438 [math.NT], 2010. %H A193181 J. Cilleruelo, <a href="http://dx.doi.org/10.1112/S0010437X10005191">The least common multiple of a quadratic sequence</a>, Compos. Math. 147 (2011), no. 4, 1129-1150. %H A193181 Bakir Farhi, <a href="https://doi.org/10.1016/j.jnt.2006.10.017">Nontrivial lower bounds for the least common multiple of some finite sequences of integers</a>, J. Number Theory, 125 (2007), p. 393-411. %H A193181 Steven Finch, <a href="/A003418/a003418.pdf">Cilleruelo's LCM Constants</a>, 2013. [Cached copy, with permission of the author] %H A193181 Juanjo Rué, Paulius Šarka, and Ana Zumalacárregui, <a href="http://arxiv.org/abs/1110.0939">On the error term of the logarithm of the lcm of a quadratic sequence</a>, arXiv:1110.0939 [math.NT], 2011. %H A193181 Juanjo Rué, Paulius Šarka, and Ana Zumalacárregui, <a href="http://dx.doi.org/10.5802/jtnb.843">On the error term of the logarithm of the lcm of a quadratic sequence</a>, Journal de théorie des nombres de Bordeaux, 25 no. 2 (2013), p. 457-470. %H A193181 <a href="/index/Lc#lcm">Index entries for sequences related to lcm's</a> %p A193181 a[0]:= 1: %p A193181 for n from 1 to 30 do a[n]:= ilcm(a[n-1],n^2+1) od: %p A193181 seq(a[i],i=1..30); # _Robert Israel_, Mar 13 2016 %t A193181 f[x_] := x^2+1; a[1] = f[1]; a[n_] := a[n] = LCM[f[n],a[n-1]]; Table[a[n], {n,20}] %o A193181 (PARI) a(n)=lcm(vector(n,k,k^2+1)) \\ _Charles R Greathouse IV_, Jul 26 2013 %Y A193181 Cf. A002313, A002522, A003418. %K A193181 nonn %O A193181 1,1 %A A193181 _José María Grau Ribas_, Jul 17 2011