login
a(1)=1; for n >= 1, a(n+1) = lcm(a(n),n) / gcd(a(n),n).
5

%I #28 Sep 09 2015 19:48:59

%S 1,1,2,6,6,30,5,35,280,2520,252,2772,231,3003,858,1430,5720,97240,

%T 437580,8314020,415701,969969,176358,4056234,2704156,67603900,2600150,

%U 70204050,10029150,290845350,9694845,300540195,9617286240,35263382880,1037158320

%N a(1)=1; for n >= 1, a(n+1) = lcm(a(n),n) / gcd(a(n),n).

%C a(n+1) = Product(A098666(n,k): 1<=k<=n), row-products of triangle A098666. - _Reinhard Zumkeller_, Sep 20 2004

%C a(n+1) is divisible by all primes in (n/2, n]; thus lim_{n->infinity} a(n) = infinity. - _Franklin T. Adams-Watters_, Dec 13 2006

%H Vincenzo Librandi, <a href="/A008339/b008339.txt">Table of n, a(n) for n = 1..1000</a>

%F a(1) = 1, a(n) = a(n-1)*r/s where y is the largest divisor of a(n-1) with r*s = n. - _Amarnath Murthy_, Jul 01 2003

%F a(1) = 1, a(n+1) = a(n)*n/gcd(a(n),n)^2. - _Franklin T. Adams-Watters_, Dec 13 2006

%p A008339 := proc(n) option remember; if n = 1 then 1 else lcm(A008339(n-1), n-1)/gcd(A008339(n-1), n-1); fi; end;

%t FoldList[ LCM[ #1, #2 ]/GCD[ #1, #2 ]&, 1, Range[ 30 ] ] (* _Olivier GĂ©rard_, Aug 15 1997 *)

%Y Cf. A249831.

%K nonn

%O 1,3

%A _N. J. A. Sloane_.