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A302350 Instance of a permutation of the positive integers such that lcm(a(n), a(n+1)) <= c*n*log(n)^2. 8
1, 6, 3, 15, 30, 10, 5, 20, 2, 140, 35, 70, 210, 105, 21, 42, 14, 7, 77, 154, 770, 385, 55, 110, 330, 165, 33, 66, 22, 11, 143, 429, 858, 286, 2002, 91, 273, 546, 182, 910, 455, 65, 130, 390, 195, 39, 78, 26, 13, 221, 663, 1326, 442, 4862, 187, 561, 1122, 374, 2618, 119, 357, 714, 238, 1190, 595, 85, 170, 510, 255, 51, 102, 34, 17 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,2

COMMENTS

For details of the construction see [Mazet & Saias].

This sequence is also a "chain": a(n) is either a divisor or a multiple of a(n+1).

Another instance of a "permutation-chain" is: A064736.

LINKS

Michel Marcus, Table of n, a(n) for n = 1..5168 (for 26 iterations)

Y.-G. Chen and C.-S. Ji, The permutation of integers with small least common multiple of two subsequent terms, Acta Math. Hungarica 132(2011), 307-309.

P. Erdős, R. Freud, and N. Hegyvári, Arithmetical properties of permutations of integers, Acta Mathematica Hungarica 41:1-2 (1983), pp 169-176.

Michel Marcus, PARI scripts

Pierre Mazet, Eric Saias, Etude du graphe divisoriel 4, arXiv:1803.10073 [math.NT], 2018.

G. Tenenbaum, Sur un problème de crible et ses applications, Annales scientifiques de l'École Normale Supérieure, 4ème série, tome 19, n°1, (1986), p.1-30.

G. Tenenbaum, Sur un problème de crible et ses applications. II. Corrigendum et étude du graphe divisoriel, Annales scientifiques de l'École Normale Supérieure, Série 4 : Tome 28 (1995) no. 2 , p. 115-127.

Index entries for sequences that are permutations of the natural numbers

PROG

(PARI) See links.

CROSSREFS

Cf. A064736.

Sequence in context: A097917 A116570 A225503 * A046879 A248267 A236415

Adjacent sequences:  A302347 A302348 A302349 * A302351 A302352 A302353

KEYWORD

nonn

AUTHOR

Michel Marcus, Apr 06 2018

STATUS

approved

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Last modified August 21 23:04 EDT 2019. Contains 326169 sequences. (Running on oeis4.)