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 A075070 a(n) = n-th compositorial number / (product of those primes which divide the n-th compositorial number). 1
 1, 2, 4, 32, 288, 576, 6912, 13824, 207360, 3317760, 59719680, 1194393600, 25082265600, 50164531200, 1203948748800, 30098718720000, 60197437440000, 1625330810880000, 45509262704640000, 1365277881139200000 (list; graph; refs; listen; history; text; internal format)
 OFFSET 0,2 COMMENTS Smallest integer of the form 'Product of first n composite number/ product of first k primes'. Divide Compositorial(n) by Primorial(k) choosing k to give the smallest integer. (k+1)-th prime does not divide a(n). LINKS FORMULA A036691/(prime factors of A036691) EXAMPLE a(0) = 1, a(5) = (4*6*8*9*10)/(2*3*5) = 576, 10 is the fifth composite number. MATHEMATICA Composite[n_] := FixedPoint[n + PrimePi[ # ] + 1 &, n + PrimePi[n] + 1]; PrimeFactors[n_] := Flatten[ Table[ # [[1]], {1}] & /@ FactorInteger[n]]; Table[ Product[ Composite[i], {i, 1, n}]/ Times @@ PrimeFactors[ Product[ Composite[i], {i, 1, n}]], {n, 0, 20}] CROSSREFS Cf. A002808. Sequence in context: A019060 A247014 A085055 * A144937 A009110 A225170 Adjacent sequences: A075067 A075068 A075069 * A075071 A075072 A075073 KEYWORD nonn AUTHOR Amarnath Murthy, Sep 08 2002 EXTENSIONS Edited and extended by Robert G. Wilson v, Jul 15 2003 Further edited by N. J. A. Sloane, Sep 13 2008 at the suggestion of R. J. Mathar STATUS approved

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Last modified March 22 20:34 EDT 2023. Contains 361433 sequences. (Running on oeis4.)