A071224 LCM of n and n-th composite number.

4, 6, 24, 36, 10, 12, 14, 120, 144, 90, 220, 84, 286, 168, 75, 208, 459, 252, 570, 160, 231, 374, 805, 72, 950, 78, 1080, 84, 1276, 90, 1426, 96, 1617, 850, 1785, 468, 1998, 2090, 2184, 2280, 2378, 420, 2666, 2772, 2880, 2990, 3102, 816, 3381

Offset: 1

Author

Amarnath Murthy, May 17 2002

Keywords

• nonn

Examples

			a(10)=90 as 18 is the 10th composite number and 10*18/gcd(10,18)=10*18/2=90.
		

Links

• Harvey P. Dale, Table of n, a(n) for n = 1..2500

Programs

Mathematica

Module[{nn=100,cmps},cmps=Select[Range[nn],CompositeQ];LCM@@@Thread[ {Range[ Length[ cmps]],cmps}]] (* Harvey P. Dale, Jul 21 2024 *)

Formula

a(n) = n*A002808(n)/A064814(n). - Lior Manor, Jun 02 2002

Extensions

More terms from Reinhard Zumkeller, May 28 2002

More terms from Lior Manor, Jun 02 2002