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A124444
a(n) = LCM of the integers, from n/2 to n, which are coprime to n.
1
1, 1, 2, 3, 12, 5, 60, 35, 280, 63, 2520, 77, 27720, 1287, 8008, 6435, 720720, 2431, 12252240, 46189, 3695120, 440895, 232792560, 96577, 1070845776, 3900225, 2974571600, 5014575, 80313433200, 215441, 2329089562800, 31556720475
OFFSET
1,3
EXAMPLE
The integers which are >= 9/2 and are <= 9 and which are coprime to 9 are 5, 7 and 8. So a(9) = lcm(5,7,8) = 280.
MATHEMATICA
f[n_] := LCM @@ Select[Range[Ceiling[n/2], n], GCD[ #, n] == 1 &]; Table[f[n], {n, 33}] (* Ray Chandler, Nov 12 2006 *)
PROG
(PARI) a(n) = lcm(select(x->(gcd(x, n)==1), vector(n\2, k, n\2+k))); \\ Michel Marcus, Mar 18 2018
CROSSREFS
Cf. A124443.
Sequence in context: A281850 A282216 A245678 * A038610 A334313 A325760
KEYWORD
nonn
AUTHOR
Leroy Quet, Nov 01 2006
EXTENSIONS
Extended by Ray Chandler, Nov 12 2006
STATUS
approved