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 A038610 Least common multiple of integers less than and prime to n. 13
 1, 1, 2, 3, 12, 5, 60, 105, 280, 63, 2520, 385, 27720, 6435, 8008, 45045, 720720, 85085, 12252240, 2909907, 3695120, 1322685, 232792560, 37182145, 1070845776, 128707425, 2974571600, 717084225, 80313433200, 215656441, 2329089562800 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,3 COMMENTS 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 a(n) = lcm(A038566(n,k): k = 1..A000010(n)). - Reinhard Zumkeller, Sep 21 2013 LINKS T. D. Noe, Table of n, a(n) for n=1..200 FORMULA 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 EXAMPLE Since 1, 5, 7, and 11 are relatively prime to 12, a(12) = LCM(1,5,7,11) = 385. MAPLE A038610 := n -> ilcm(op(select(k->igcd(n, k)=1, [\$1..n]))); # Peter Luschny, Jun 25 2011 MATHEMATICA Table[ LCM@@ Flatten[ Position[ GCD[ n, # ]& /@ Range[ n ], 1 ] ], {n, 32} ] Join[{1}, Table[LCM@@Select[Range[n-1], CoprimeQ[#, n]&], {n, 2, 40}]] (* Harvey P. Dale, Mar 05 2016 *) PROG (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 (Haskell) a038610 = foldl lcm 1 . a038566_row -- Reinhard Zumkeller, Sep 21 2013, Oct 04 2011 CROSSREFS Cf. A034699, A000005. Sequence in context: A282216 A245678 A124444 * A056819 A124442 A220271 Adjacent sequences:  A038607 A038608 A038609 * A038611 A038612 A038613 KEYWORD nonn,nice AUTHOR STATUS approved

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Last modified October 20 17:39 EDT 2018. Contains 316394 sequences. (Running on oeis4.)