A073329 a(n) is the n-th number to have n distinct prime factors.

2, 10, 60, 420, 4290, 53130, 903210, 17687670, 406816410, 11125544430, 338431883790, 11833068917670, 457077357006270, 20384767656323070, 955041577211912190, 49230430891074322890, 2740956243836856315270, 168909608387276001835590, 11054926927790884163355330

Offset: 1

Author

Robert G. Wilson v, Aug 22 2002

Keywords

• nonn

Examples

			a(1) = 2 because 2 is the first number to have one prime factor.
a(2) = 10 because 10 is the second number to have two prime factors; 6 is the first.
a(3) = 60 = 2*2*3*5 because 60 is the third number to have three prime factors (2,3,5); 30 is the first and 42 is the second.
		

Links

• David A. Corneth, Table of n, a(n) for n = 1..350 (terms <= 10^1000)

Crossrefs

a(n) is last term in n-th row of A048692.

Cf. A001221, A001222, A340467.

Formula

A001221(a(n)) = n <= A001222(a(n)). - Alois P. Heinz, Jan 09 2021

Extensions

Edited by Dean Hickerson, Nov 03 2002

More terms from Sascha Kurz, Jan 03 2003

Corrected from a(9) onwards by T. D. Noe, Dec 01 2004

More terms from David A. Corneth, Jan 09 2021