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 A075059 a(n) = 1 + lcm(1, 2, ..., n) = 1 + A003418(n). 7
 2, 2, 3, 7, 13, 61, 61, 421, 841, 2521, 2521, 27721, 27721, 360361, 360361, 360361, 720721, 12252241, 12252241, 232792561, 232792561, 232792561, 232792561, 5354228881, 5354228881, 26771144401, 26771144401, 80313433201, 80313433201 (list; graph; refs; listen; history; text; internal format)
 OFFSET 0,1 COMMENTS Consider the triangle in which the n-th row contains the second run of n consecutive numbers such that the r-th term is divisible by r. Sequence gives the first column of the triangle. The first run trivially begins with 1. Also the smallest of n consecutive integers (with the first greater than 1) divisible respectively by 1, 2, 3, ..., n. - Robert G. Wilson v, Oct 30 2014 LINKS FORMULA a(n) = 1 + A003418(n). EXAMPLE First column of the triangle A075061:    2;    3,  4;    7,  8,  9;   13, 14, 15, 16;   61, 62, 63, 64, 65;   61, 62, 63, 64, 65, 66;   ... MATHEMATICA Table[LCM@@Range[n] + 1, {n, 30}] (* Harvey P. Dale, Nov 15 2011 *) PROG (MAGMA) [Exponent(SymmetricGroup(n))+1 : n in [1..30]]; // Vincenzo Librandi, Oct 31 2014 (PARI) a(n)=lcm([1..n])+1 \\ Charles R Greathouse IV, Nov 04 2014 CROSSREFS Cf. A003418, A060401, A065500, A070198, A072562, A075061, A249051. Sequence in context: A184841 A109277 A093437 * A060357 A064714 A152255 Adjacent sequences:  A075056 A075057 A075058 * A075060 A075061 A075062 KEYWORD nonn AUTHOR Amarnath Murthy, Sep 08 2002 EXTENSIONS New definition from Vladeta Jovovic, Jun 16 2003 Edited by N. J. A. Sloane, Jul 01 2008 at the suggestion of R. J. Mathar a(0)=2 prepended by Max Alekseyev, Sep 04 2015 STATUS approved

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Last modified July 21 17:20 EDT 2019. Contains 325198 sequences. (Running on oeis4.)