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A319865 Product of distinct prime factors of highly composite numbers (definition 1, A002182). 1
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 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,2

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

FORMULA

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

EXAMPLE

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

CROSSREFS

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

Sequence in context: A086447 A324032 A196872 * A140219 A259225 A300951

Adjacent sequences:  A319862 A319863 A319864 * A319866 A319867 A319868

KEYWORD

nonn

AUTHOR

Seiichi Manyama, Sep 29 2018

STATUS

approved

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Last modified July 12 17:40 EDT 2020. Contains 335665 sequences. (Running on oeis4.)