A114797 a(n) = n multiplied by the least nontrivial nondivisor of n.

6, 12, 10, 24, 14, 24, 18, 30, 22, 60, 26, 42, 30, 48, 34, 72, 38, 60, 42, 66, 46, 120, 50, 78, 54, 84, 58, 120, 62, 96, 66, 102, 70, 180, 74, 114, 78, 120, 82, 168, 86, 132, 90, 138, 94, 240, 98, 150, 102, 156, 106, 216, 110, 168, 114, 174, 118, 420, 122, 186, 126, 192

Offset

3,1

Comments

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!.

Links

Harvey P. Dale, Table of n, a(n) for n = 3..1000

Example

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

Mathematica

Do[l = Range[1, n]; m = Divisors[n]; s = Complement[l, m]; Print[n * Min[s]], {n, 3, 100}] (* Ryan Propper, Jul 21 2006 *)
# First[Complement[Range[#], Divisors[#]]]&/@Range[3, 70] (* Harvey P. Dale, Dec 27 2012 *)

Crossrefs

Sequence in context: A134383 A366144 A272305 * A048726 A092461 A102809

Adjacent sequences: A114794 A114795 A114796 * A114798 A114799 A114800

Keyword

nonn

Author

Amarnath Murthy, Nov 20 2005

Extensions

More terms from Ryan Propper, Jul 21 2006

Status

approved