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 A189100 a(n) = lcm(n!,n!')/gcd(n!,n!'), where n!' is the arithmetic derivative of n! (A068311). 5
 0, 2, 30, 66, 1830, 645, 33180, 198870, 228270, 64785, 7960260, 9738960, 1663226565, 7232635410, 857066210, 1057466410, 307311194190, 767464487790, 278292627277665, 306517823106495, 35302033071305, 147385363695570, 78207294248313230, 198777858520921680 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,2 COMMENTS Least common multiple of n! and its arithmetic derivative divided by greatest common divisor of n! and its arithmetic derivative. LINKS Nathaniel Johnston, Table of n, a(n) for n = 1..200 FORMULA a(n) = lcm(n!,n!')/gcd(n!,n!') = A086130(n!)/A085731(n!) = lcm(A000142(n),A068311(n))/gcd(A000142(n),A068311(n)) EXAMPLE n = 5: 5! = 120, 120' = 244, gcd(120,244) = 4, lcm(120,244) = 7320, 7320/4 = 1830 -> a(5) = 1830. CROSSREFS A068311, A083346, A083346, A085731, A086130 Sequence in context: A105403 A134644 A244379 * A085637 A193177 A157870 Adjacent sequences: A189097 A189098 A189099 * A189101 A189102 A189103 KEYWORD nonn AUTHOR Giorgio Balzarotti, Apr 16 2011 STATUS approved

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Last modified June 8 07:54 EDT 2023. Contains 363157 sequences. (Running on oeis4.)