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 A007956 Product of proper divisors of n. 29
 1, 1, 1, 2, 1, 6, 1, 8, 3, 10, 1, 144, 1, 14, 15, 64, 1, 324, 1, 400, 21, 22, 1, 13824, 5, 26, 27, 784, 1, 27000, 1, 1024, 33, 34, 35, 279936, 1, 38, 39, 64000, 1, 74088, 1, 1936, 2025, 46, 1, 5308416, 7, 2500, 51, 2704, 1, 157464, 55, 175616, 57, 58, 1, 777600000, 1, 62, 3969, 32768, 65 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,4 LINKS T. D. Noe, Table of n, a(n) for n = 1..1000 FORMULA a(n) = A007955(n)/n = n^(A000005(n)/2-1) = sqrt(n^(number of factors of n other than 1 and n)) a(n) = Product_{k=1..A000005(n)-1} A027751(n,k). - Reinhard Zumkeller, Feb 04 2013 a(n) = A240694(n, A000005(n)-1) for n > 1. - Reinhard Zumkeller, Apr 10 2014 MAPLE A007956 := n -> mul(i, i=op(numtheory[divisors](n) minus {1, n})); seq(A007956(i), i=1..79); # Peter Luschny, Mar 22 2011 MATHEMATICA Table[Times@@Most[Divisors[n]], {n, 65}] (* Alonso del Arte, Apr 18 2011 *) a[n_] := n^(DivisorSigma[0, n]/2 - 1); Table[a[n], {n, 1, 65}] (* Jean-François Alcover, Oct 07 2013 *) PROG (PARI) A007956(n) = local(a); a=1; fordiv(n, d, a=a*d); a/n \\ Michael B. Porter, Dec 01 2009 (PARI) a(n)=my(k); if(issquare(n, &k), k^(numdiv(n)-2), n^(numdiv(n)/2-1)) \\ Charles R Greathouse IV, Oct 15 2015 (Haskell) a007956 = product . a027751_row -- Reinhard Zumkeller, Feb 04 2013, Nov 02 2011 CROSSREFS Cf. A000005, A007955, A048671, A182936, A027751, A066729. Cf. A007422 (fixed points). Cf. A001065 (sums of proper divisors). Sequence in context: A166120 A318256 A264859 * A107754 A181569 A274085 Adjacent sequences:  A007953 A007954 A007955 * A007957 A007958 A007959 KEYWORD nonn,easy,nice AUTHOR R. Muller EXTENSIONS More terms from Scott Lindhurst (ScottL(AT)alumni.princeton.edu) STATUS approved

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Last modified January 23 09:21 EST 2019. Contains 319383 sequences. (Running on oeis4.)