cp's OEIS Frontend

This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.

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).

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%I A330524 #14 Dec 18 2019 14:29:55
%S A330524 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,
%T A330524 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,
%U A330524 2,18,4,16,3,10,5,10,6,5,11,4,17,3,11,5,14
%N 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).
%C A330524 This sequence is a binary variant of A318225.
%C A330524 This sequence has similarities with A088177; here we combine successive terms by concatenation, there by multiplication.
%C A330524 This sequence is necessarily unbounded.
%C A330524 Also, the value 1 appears infinitely many times.
%H A330524 Rémy Sigrist, <a href="/A330524/b330524.txt">Table of n, a(n) for n = 1..10000</a>
%e A330524 The first terms, alongside their binary representation and that of the concatenation of two consecutive terms, are:
%e A330524   n   a(n)  bin(a(n))  bin(a(n)|a(n+1))
%e A330524   --  ----  ---------  ----------------
%e A330524    1     1          1                11
%e A330524    2     1          1               110
%e A330524    3     2         10               101
%e A330524    4     1          1               111
%e A330524    5     3         11              1110
%e A330524    6     2         10              1010
%e A330524    7     2         10              1011
%e A330524    8     3         11              1111
%e A330524    9     3         11             11100
%e A330524   10     4        100              1001
%e A330524   11     1          1              1100
%e A330524   12     4        100             10010
%o A330524 (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)))
%Y A330524 See A330525 for the concatenation of consecutive terms.
%Y A330524 Cf. A088177, A163621, A318225.
%K A330524 nonn,base
%O A330524 1,3
%A A330524 _Rémy Sigrist_, Dec 17 2019