cp's OEIS Frontend

This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.

Showing 1-3 of 3 results.

A338159 The least number which can be represented as a product of the greatest number of distinct positive integers in exactly n ways.

Original entry on oeis.org

1, 12, 60, 96, 360, 576, 480, 15120, 864, 2880, 3360, 6912, 25200, 7680, 20160, 36960, 4320, 93312, 46080, 82944, 221760, 34560, 2494800, 311040, 53760, 88200, 15966720, 30240, 3880800, 1995840, 43200, 322560, 388800, 345600, 970200, 241920, 414720, 5832000, 529200, 5598720
Offset: 1

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Author

Vladimir Letsko, Oct 14 2020

Keywords

Comments

k = p_1^2*p_2*...*p_n obviously has exactly n required representations. Hence a(n) exists for any n.
a(n) is the least k such that A338160(k) = n.
All terms are in A025487.

Examples

			a(60) = 3 because 60 = 2*3*10 = 2*5*6 = 3*4*5 and each number less than 60 does not have exactly 3 such representations (adding the factor 1 to each product doesn't change anything).
		

Crossrefs

Cf. A338160.

Formula

a(A338160(n)) = n.
A338160(k) <> n for k < a(n).

Extensions

a(23)-a(40) from Andrew Howroyd, Oct 14 2020

A340033 a(n) is the largest number of distinct numbers whose product is A025487(n).

Original entry on oeis.org

1, 2, 2, 3, 3, 3, 3, 4, 4, 3, 4, 4, 4, 4, 4, 4, 5, 4, 5, 5, 5, 5, 5, 5, 4, 5, 5, 5, 5, 5, 5, 4, 5, 6, 5, 6, 5, 5, 6, 5, 6, 6, 6, 6, 6, 5, 6, 6, 6, 6, 5, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 5, 6, 6, 6, 7, 6, 6, 7, 6, 6, 7, 7, 6, 7, 7, 6, 6, 5, 7, 6, 7, 7, 7, 7, 7, 6
Offset: 1

Views

Author

David A. Corneth, Feb 04 2021

Keywords

Examples

			a(11) = 4 as A025487(11) = 36, which can be expressed as a product of at most 4 distinct positive integers via 1 * 2 * 3 * 6.
		

Crossrefs

A340034 a(n) is the number of ways to represent A025487(n) as a product of the largest possible number of distinct factors in the product.

Original entry on oeis.org

1, 1, 1, 1, 1, 2, 1, 1, 1, 2, 1, 2, 3, 1, 3, 4, 1, 1, 1, 1, 1, 1, 1, 3, 2, 2, 5, 2, 4, 4, 7, 3, 6, 1, 4, 1, 9, 7, 1, 1, 1, 1, 1, 1, 3, 7, 4, 2, 2, 3, 1, 6, 2, 1, 7, 3, 10, 1, 11, 5, 9, 7, 2, 17, 5, 5, 1, 9, 11, 1, 2, 10, 1, 1, 12, 1, 1, 14, 9, 3, 2, 10, 1, 4, 1
Offset: 1

Views

Author

David A. Corneth, Feb 04 2021

Keywords

Examples

			a(13) = 3 as there are three ways to represent A025487(13) = 60 as a product of largest possible number of distinct factors in the product. That number is 4 and the products are 1 * 2 * 3 * 10 = 1 * 2 * 5 * 6 = 1 * 3 * 4 * 5 = 60.
		

Crossrefs

Showing 1-3 of 3 results.