A080498 a(n) = (n-c_1)(n-c_2)...(n-c_k) where c_k is the k-th composite number and is also the largest composite number < n.

1, 1, 1, 1, 1, 2, 3, 8, 15, 48, 210, 1152, 3780, 19200, 62370, 322560, 2162160, 17418240, 81081000, 567705600, 2481078600, 16907304960, 146659312800, 1504935936000, 8799558768000, 76435881984000, 819678899239200

Offset: 1

Author

Amarnath Murthy, Mar 19 2003

Keywords

• nonn

Examples

			a(6) = (6-4) = 2. a(10) = (10-4)(10-6)(10-8)(10-9) = 48.
		

Links

• Harvey P. Dale, Table of n, a(n) for n = 1..539

Crossrefs

Cf. A080497, A072513, A080500.

Programs

Mathematica

Module[{nn=30,cmps},cmps=Select[Range[nn],CompositeQ];Table[Times@@(n-Select[ cmps,#Harvey P. Dale, Aug 13 2024 *)

Extensions

More terms from Antonio G. Astudillo (afg_astudillo(AT)lycos.com), Apr 06 2003