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A360281
Lexicographically earliest sequence of distinct positive integers such that for any n > 2, a(n) is a divisor or a multiple of a(n-1) + a(n-2).
1
1, 2, 3, 5, 4, 9, 13, 11, 6, 17, 23, 8, 31, 39, 7, 46, 53, 33, 43, 19, 62, 27, 89, 29, 59, 22, 81, 103, 92, 15, 107, 61, 12, 73, 85, 79, 41, 10, 51, 122, 173, 295, 18, 313, 331, 14, 69, 83, 38, 121, 159, 20, 179, 199, 21, 44, 65, 109, 58, 167, 25, 16, 82, 49
OFFSET
1,2
COMMENTS
This sequence has similarities with A085947, A328444 and A332301:
- these sequences agree for n = 1..39,
- however, a(40) = 122,
A085947(40) does not exist,
A328444(40) = 34,
A332301(40) = 61.
LINKS
Rémy Sigrist, PARI program.
EXAMPLE
The first terms, alongside the relationship with the two prior terms, are:
n a(n) Relationship
-- ---- ------------
1 1 N/A
2 2 N/A
3 3 2+1
4 5 3+2
5 4 (5+3)/2
6 9 4+5
7 13 9+4
8 11 (13+9)/2
9 6 (11+13)/4
10 17 6+11
11 23 17+6
12 8 (23+17)/5
PROG
(PARI) \\ See Links section.
CROSSREFS
KEYWORD
nonn
AUTHOR
Rémy Sigrist, Feb 01 2023
STATUS
approved