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A375579
Lexicographically earliest sequence of distinct positive integers such that the products of two consecutive terms belong to A055932.
2
1, 2, 3, 4, 6, 5, 12, 8, 9, 10, 15, 14, 30, 7, 60, 16, 18, 20, 21, 40, 24, 25, 36, 27, 32, 45, 28, 75, 42, 35, 48, 50, 54, 64, 72, 70, 33, 140, 63, 80, 81, 90, 49, 120, 56, 105, 22, 210, 11, 420, 44, 315, 66, 175, 84, 55, 126, 100, 96, 108, 125, 144, 128, 135
OFFSET
1,2
COMMENTS
a(n+1) is a multiple of A083720(a(n)).
This sequence has similarities with A175343; here we consider prime factors of consecutive terms, there ones in binary expansions of consecutive terms.
LINKS
Rémy Sigrist, PARI program
EXAMPLE
The first terms, alongside their prime factors, are:
n a(n) 2 3 5 7
-- ---- - - - -
1 1
2 2 X
3 3 X
4 4 X
5 6 X X
6 5 X
7 12 X X
8 8 X
9 9 X
10 10 X X
11 15 X X
12 14 X X
PROG
(PARI) \\ See Links section.
CROSSREFS
KEYWORD
nonn
AUTHOR
Rémy Sigrist, Aug 19 2024
STATUS
approved