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A336200
Lexicographically earliest sequence of distinct terms such that every integer k appears twice, at distance a(k).
1
1, 1, 2, 2, 3, 4, 3, 4, 5, 6, 8, 5, 7, 6, 8, 7, 9, 10, 11, 12, 13, 9, 14, 10, 12, 15, 11, 13, 14, 16, 17, 18, 19, 15, 20, 21, 16, 23, 22, 17, 24, 18, 25, 19, 26, 27, 20, 22, 21, 28, 24, 23, 29, 30, 25, 31, 27, 32, 33, 26, 35, 34, 28, 36, 38, 37, 29, 39, 40, 30
OFFSET
1,3
COMMENTS
This sequence combines features of A001462 and of A026242.
LINKS
EXAMPLE
For n = 1:
- we can choose a(1) = 1,
- and then a(1+a(1)) = a(2) = 1.
For n = 3:
- we can choose a(3) = 2,
- and then a(3+a(2)) = a(4) = 2.
For n = 5:
- we can choose a(5) = 3,
- and then a(5+a(3)) = a(7) = 3.
PROG
(PARI) See Links section.
CROSSREFS
Sequence in context: A162619 A259196 A357589 * A032355 A308597 A205153
KEYWORD
nonn
AUTHOR
Rémy Sigrist, Jul 11 2020
STATUS
approved