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A308471 Lowest outliers for A057660. 1
1, 4, 6, 12, 24, 30, 60, 120, 180, 210, 360, 420, 840, 1260, 2520, 4620, 9240, 13860, 27720, 55440, 60060, 120120, 180180, 360360, 720720, 1441440, 1801800, 2042040, 3063060, 6126120, 12252240, 24504480, 30630600, 36756720, 38798760 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,2

COMMENTS

A057660(n) is a multiplicative function bounded above by n*(n-1)+1, which is reached whenever n is 1 or prime. These numbers are the n such that the ratio between A057660(n) and the upper bound reaches a record low.

Motivated by Daniel Forgues's conjecture that this sequence consists of 4 and A051451.

A subsequence of A025487.

LINKS

Charlie Neder, Table of n, a(n) for n = 1..215

EXAMPLE

A057660(60060)/(60060*60059+1) = 1211716737/3607143541 ~ 0.3359214, and every number less than 60060 has a ratio > 0.34, so 60060 is in this sequence.

CROSSREFS

Cf. A057660, A025487, A051451.

Sequence in context: A054167 A303198 A120211 * A095416 A162688 A070232

Adjacent sequences:  A308468 A308469 A308470 * A308472 A308473 A308474

KEYWORD

nonn

AUTHOR

Charlie Neder, May 29 2019

STATUS

approved

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Last modified October 22 22:34 EDT 2019. Contains 328335 sequences. (Running on oeis4.)