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A318225
Lexicographically earliest sequence of positive terms such that the concatenation of two consecutive terms is always unique.
2
1, 1, 2, 1, 3, 1, 4, 1, 5, 1, 6, 1, 7, 1, 8, 1, 9, 1, 10, 1, 11, 2, 2, 3, 2, 4, 2, 5, 2, 6, 2, 7, 2, 8, 2, 9, 2, 10, 2, 11, 3, 3, 4, 3, 5, 3, 6, 3, 7, 3, 8, 3, 9, 3, 10, 3, 11, 4, 4, 5, 4, 6, 4, 7, 4, 8, 4, 9, 4, 10, 4, 11, 5, 5, 6, 5, 7, 5, 8, 5, 9, 5, 10, 5
OFFSET
1,3
COMMENTS
In other words, for any distinct i and j, A066686(a(i), a(i+1)) <> A066686(a(j), a(j+1)).
The sequence b such that for any n > 0, b(n) = A066686(a(n), a(n+1)), satisfies b(n) = A303446(n+1) for n = 1..116 and b(117) <> A303446(118).
The sequence contains long runs of consecutive terms where one term out of two equals 1.
EXAMPLE
The first terms, alongside the concatenation of a(n) and of a(n+1), are:
n a(n) A066686(a(n), a(n+1))
-- ---- ---------------------
1 1 11
2 1 12
3 2 21
4 1 13
5 3 31
6 1 14
7 4 41
8 1 15
9 5 51
10 1 16
11 6 61
12 1 17
13 7 71
14 1 18
15 8 81
16 1 19
17 9 91
18 1 110
19 10 101
20 1 111
21 11 112
22 2 22
23 2 23
24 3 32
25 2 24
PROG
(C++) See Links section.
CROSSREFS
Sequence in context: A152271 A133622 A158416 * A360257 A335497 A309872
KEYWORD
nonn,base,look
AUTHOR
Rémy Sigrist, Aug 21 2018
STATUS
approved