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A258324 Least common multiple of all n - d, where d < n and d is a divisor of n.

%I A258324 #16 Mar 13 2018 04:08:37
%S A258324 1,1,2,6,4,60,6,84,24,360,10,3960,12,1092,420,840,16,12240,18,13680,
%T A258324 1260,4620,22,1275120,120,7800,936,19656,28,1096200,30,52080,5280,
%U A258324 17952,7140,5654880,36,25308,8892,2489760,40,1343160,42,397320,27720
%N A258324 Least common multiple of all n - d, where d < n and d is a divisor of n.
%C A258324 a(n) is a divisor of A072513(n).
%C A258324 a(n) = n-1 if and only if n is prime. - _Robert Israel_, May 26 2015
%H A258324 Ivan Neretin, <a href="/A258324/b258324.txt">Table of n, a(n) for n = 1..1000</a>
%F A258324 a(n) = lcm(n-d_1, n-d_2, ..., n-d_k) where d_i are the aliquot divisors of n.
%e A258324 a(9) = lcm(9-1, 9-3) = lcm(8, 6) = 24.
%p A258324 f:= n -> ilcm(seq(n-d, d = numtheory:-divisors(n) minus {n})):
%p A258324 map(f,[$ 1 .. 100]); # _Robert Israel_, May 26 2015
%t A258324 Table[If[n == 1, 1, LCM @@ (n - Most[Divisors[n]])], {n, 50}]
%o A258324 (PARI) a(n)=lcm(apply(d->if(d<n,n-d,1),divisors(n))) \\ _Charles R Greathouse IV_, May 26 2015
%o A258324 (Haskell)
%o A258324 a258324 n = foldl lcm 1 $ map (n -) $ a027751_row n
%o A258324 -- _Reinhard Zumkeller_, May 27 2015
%Y A258324 Cf. A072513 (product instead of LCM).
%Y A258324 Cf. A027751.
%K A258324 nonn
%O A258324 1,3
%A A258324 _Ivan Neretin_, May 26 2015