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A330524
Lexicographically earliest sequence of positive terms such that for any distinct i and j, a(i) | a(j+1) <> a(j) | a(j+1) (where "|" corresponds to binary concatenation, A163621).
2
1, 1, 2, 1, 3, 2, 2, 3, 3, 4, 1, 4, 2, 4, 3, 5, 2, 5, 3, 6, 1, 8, 1, 9, 2, 8, 2, 9, 3, 7, 4, 4, 5, 4, 8, 3, 8, 4, 9, 4, 10, 2, 11, 2, 13, 1, 10, 4, 11, 3, 9, 5, 8, 5, 9, 6, 4, 15, 2, 16, 1, 16, 2, 17, 2, 18, 4, 16, 3, 10, 5, 10, 6, 5, 11, 4, 17, 3, 11, 5, 14
OFFSET
1,3
COMMENTS
This sequence is a binary variant of A318225.
This sequence has similarities with A088177; here we combine successive terms by concatenation, there by multiplication.
This sequence is necessarily unbounded.
Also, the value 1 appears infinitely many times.
LINKS
EXAMPLE
The first terms, alongside their binary representation and that of the concatenation of two consecutive terms, are:
n a(n) bin(a(n)) bin(a(n)|a(n+1))
-- ---- --------- ----------------
1 1 1 11
2 1 1 110
3 2 10 101
4 1 1 111
5 3 11 1110
6 2 10 1010
7 2 10 1011
8 3 11 1111
9 3 11 11100
10 4 100 1001
11 1 1 1100
12 4 100 10010
PROG
(PARI) s=0; v=1; for (n=1, 81, print1 (v", "); for (w=1, oo, if (!bittest(s, k=v*2^#binary(w)+w), s+=2^k; v=w; break)))
CROSSREFS
See A330525 for the concatenation of consecutive terms.
Sequence in context: A205784 A066272 A237130 * A336037 A058773 A122805
KEYWORD
nonn,base
AUTHOR
Rémy Sigrist, Dec 17 2019
STATUS
approved