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 A038610 #31 Jun 20 2019 02:58:18 %S A038610 1,1,2,3,12,5,60,105,280,63,2520,385,27720,6435,8008,45045,720720, %T A038610 85085,12252240,2909907,3695120,1322685,232792560,37182145,1070845776, %U A038610 128707425,2974571600,717084225,80313433200,215656441,2329089562800 %N A038610 Least common multiple of integers less than and prime to n. %C A038610 If n is a prime power, tau(a(n)) is the number of times n occurs in A034699. (If n is not a prime power, it does not occur in A034699.) - _Franklin T. Adams-Watters_, Apr 01 2008 %C A038610 a(n) = lcm(A038566(n,k): k = 1..A000010(n)). - _Reinhard Zumkeller_, Sep 21 2013 %H A038610 T. D. Noe, <a href="/A038610/b038610.txt">Table of n, a(n) for n=1..200</a> %F A038610 a(n) = e^[Sum_{k=1..n} (1-floor(n^k/k)+floor((n^k -1)/k))*Mangoldt(k)] where Mangoldt is the Mangoldt function. - _Anthony Browne_, Jun 16 2016 %e A038610 Since 1, 5, 7, and 11 are relatively prime to 12, a(12) = LCM(1,5,7,11) = 385. %p A038610 A038610 := n -> ilcm(op(select(k->igcd(n,k)=1,[$1..n]))); # _Peter Luschny_, Jun 25 2011 %t A038610 Table[ LCM@@ Flatten[ Position[ GCD[ n, # ]& /@ Range[ n ], 1 ] ], {n, 32} ] %t A038610 Join[{1},Table[LCM@@Select[Range[n-1],CoprimeQ[#,n]&],{n,2,40}]] (* _Harvey P. Dale_, Mar 05 2016 *) %o A038610 (PARI) a(n) = local(r); r=1;for(i=1,n-1,if(gcd(i,n)==1,r=lcm(r,i)));r \\ _Franklin T. Adams-Watters_, Apr 01 2008 %o A038610 (Haskell) %o A038610 a038610 = foldl lcm 1 . a038566_row %o A038610 -- _Reinhard Zumkeller_, Sep 21 2013, Oct 04 2011 %Y A038610 Cf. A034699, A000005. %K A038610 nonn,nice %O A038610 1,3 %A A038610 _Wouter Meeussen_