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A382376
Lexicographically earliest sequence of distinct positive integers such that the number of distinct prime factors of adjacent terms differ exactly by one.
3
1, 2, 6, 3, 10, 4, 12, 5, 14, 7, 15, 8, 18, 9, 20, 11, 21, 13, 22, 16, 24, 17, 26, 19, 28, 23, 33, 25, 34, 27, 35, 29, 36, 30, 38, 31, 39, 32, 40, 37, 44, 41, 45, 42, 46, 43, 48, 47, 50, 49, 51, 53, 52, 59, 54, 60, 55, 61, 56, 64, 57, 66, 58, 67, 62, 70, 63
OFFSET
1,2
COMMENTS
All primorial numbers appear in the sequence (we can use similar arguments as for A382357).
Conjecture: this sequence is a permutation of the positive integers.
LINKS
Rémy Sigrist, PARI program
EXAMPLE
The initial terms are:
n a(n) A001221(a(n))
-- ---- -------------
1 1 0
2 2 1
3 6 2
4 3 1
5 10 2
6 4 1
7 12 2
8 5 1
9 14 2
10 7 1
11 15 2
12 8 1
13 18 2
14 9 1
15 20 2
PROG
(PARI) \\ See Links section.
CROSSREFS
KEYWORD
nonn
AUTHOR
Rémy Sigrist, Mar 23 2025
STATUS
approved