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A338441 Lexicographically earliest sequence of distinct squarefree numbers such that for any prime p, any run of consecutive multiples of p has length exactly 3. 3
1, 2, 6, 30, 15, 5, 3, 21, 42, 14, 10, 35, 70, 154, 22, 11, 7, 77, 231, 33, 39, 13, 26, 34, 102, 51, 57, 19, 38, 46, 138, 69, 66, 110, 330, 105, 273, 91, 65, 55, 165, 429, 78, 130, 170, 85, 17, 23, 115, 230, 190, 114, 285, 195, 455, 182, 210, 390, 1365, 1001 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,2

COMMENTS

This sequence is a squarefree variant of A338338.

Conjecture: this is a permutation of the squarefree numbers (A005117).

LINKS

Rémy Sigrist, Table of n, a(n) for n = 1..10000

Rémy Sigrist, C program for A338441

EXAMPLE

The first terms, alongside their prime factors, are:

  n   a(n)  Prime factors

  --  ----  -------------

   1     1

   2     2  2

   3     6  2 3

   4    30  2 3 5

   5    15    3 5

   6     5      5

   7     3    3

   8    21    3   7

   9    42  2 3   7

  10    14  2     7

  11    10  2   5

  12    35      5 7

  13    70  2   5 7

  14   154  2     7 11

  15    22  2       11

  16    11          11

PROG

(C) See Links section.

CROSSREFS

Cf. A005117, A338338, A338444.

Sequence in context: A076978 A117213 A127797 * A077634 A095198 A126989

Adjacent sequences:  A338438 A338439 A338440 * A338442 A338443 A338444

KEYWORD

nonn

AUTHOR

Rémy Sigrist, Oct 28 2020

STATUS

approved

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Last modified August 5 03:00 EDT 2021. Contains 346457 sequences. (Running on oeis4.)