A114797 - OEIS

%I #11 Nov 17 2018 21:02:22

%S 6,12,10,24,14,24,18,30,22,60,26,42,30,48,34,72,38,60,42,66,46,120,50,

%T 78,54,84,58,120,62,96,66,102,70,180,74,114,78,120,82,168,86,132,90,

%U 138,94,240,98,150,102,156,106,216,110,168,114,174,118,420,122,186,126,192

%N a(n) = n multiplied by the least nontrivial nondivisor of n.

%C a(2n-1) = 4n-2. a(n!) = p*n! where p is the least prime > n, because all the number from n+1, n+2 up to p-1 would divide n!.

%H Harvey P. Dale, <a href="/A114797/b114797.txt">Table of n, a(n) for n = 3..1000</a>

%e a(24) = 24*5 = 120 as 2,3,4 divide 24.

%t Do[l = Range[1, n]; m = Divisors[n]; s = Complement[l, m]; Print[n * Min[s]], {n, 3, 100}] (* _Ryan Propper_, Jul 21 2006 *)

%t # First[Complement[Range[#],Divisors[#]]]&/@Range[3,70] (* _Harvey P. Dale_, Dec 27 2012 *)

%K nonn

%O 3,1

%A _Amarnath Murthy_, Nov 20 2005

%E More terms from _Ryan Propper_, Jul 21 2006