A072500 Product of divisors of n which are >= n^(1/2).

1, 2, 3, 8, 5, 18, 7, 32, 27, 50, 11, 288, 13, 98, 75, 512, 17, 972, 19, 1000, 147, 242, 23, 13824, 125, 338, 243, 2744, 29, 27000, 31, 4096, 363, 578, 245, 419904, 37, 722, 507, 64000, 41, 86436, 43, 10648, 6075, 1058, 47, 1769472, 343, 12500, 867, 17576, 53

Offset: 1

Author

Amarnath Murthy, Jul 20 2002

Keywords

• nonn
• changed

Comments

a(n) = n iff n is not a composite number.

Examples

			The divisors of 20 are 1, 2, 4, 5, 10 and 20. a(20) = 5*10*20 = 1000.
		

Links

• Harvey P. Dale, Table of n, a(n) for n = 1..1000

Crossrefs

Cf. A072499, A072501, A070038.

Programs

Mathematica

Table[Times @@ Select[Divisors[n], # >= Sqrt[n] &], {n, 1, 55}]

Extensions

Edited by Robert G. Wilson v, Jul 22 2002

Corrected a(16) by Harvey P. Dale, Oct 06 2011