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A372127
Lexicographically earliest sequence of distinct positive integers such that for any n > 0, a(2*n+2) = LCM(a(2*n+1), a(n+1)).
2
1, 2, 3, 6, 4, 12, 5, 30, 7, 28, 8, 24, 9, 45, 11, 330, 10, 70, 13, 364, 14, 56, 15, 120, 16, 144, 17, 765, 18, 198, 19, 6270, 21, 210, 20, 140, 22, 286, 23, 8372, 25, 350, 26, 728, 27, 135, 29, 3480, 31, 496, 32, 288, 33, 561, 34, 1530, 35, 630, 36, 396, 37
OFFSET
1,2
COMMENTS
Conjecture: this sequence is a permutation of the positive integers.
LINKS
Rémy Sigrist, PARI program
EXAMPLE
The first terms, arranged alongside a binary tree where each right child equals the least common multiple of its parent and its sibling, are:
|
1
|
.-------2-------.
| |
.---3---. .---6---.
| | | |
.-4-. .12-. .-5-. .30-.
| | | | | | | |
7 28 8 24 9 45 11 330
PROG
(PARI) \\ See Links section.
CROSSREFS
See A372030 for similar sequences.
Sequence in context: A305325 A302848 A046202 * A372031 A225642 A273317
KEYWORD
nonn
AUTHOR
Rémy Sigrist, Apr 20 2024
STATUS
approved