A319865 Product of distinct prime factors of highly composite numbers (definition 1, A002182).

1, 2, 2, 6, 6, 6, 6, 6, 30, 30, 30, 30, 30, 30, 210, 210, 210, 210, 210, 210, 210, 210, 210, 210, 2310, 210, 210, 2310, 2310, 2310, 2310, 2310, 2310, 2310, 2310, 2310, 2310, 30030, 30030, 30030, 30030, 30030, 30030, 30030, 30030, 30030, 30030, 30030, 30030, 30030, 30030, 30030, 510510, 30030

Offset: 1

Author

Seiichi Manyama, Sep 29 2018

Keywords

• nonn

Examples

			n  | A002182(n)                       | a(n)
---+----------------------------------+--------------------------
24 | 25200 = 2^4 * 3^2 * 5^2 * 7      |  210 = 2 * 3 * 5 * 7
25 | 27720 = 2^3 * 3^2 * 5   * 7 * 11 | 2310 = 2 * 3 * 5 * 7 * 11
26 | 45360 = 2^4 * 3^4 * 5   * 7      |  210 = 2 * 3 * 5 * 7
27 | 50400 = 2^5 * 3^2 * 5^2 * 7      |  210 = 2 * 3 * 5 * 7
		

Links

• Amiram Eldar, Table of n, a(n) for n = 1..10000
• Eric Weisstein's World of Mathematics, Highly Composite Number
• Wikipedia, Highly composite number

Crossrefs

Cf. A002182, A007947, A108602, A112779, A272605.

Formula

a(n) = A007947(A002182(n)). - Michel Marcus, Sep 30 2018