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.

A340717 Lexicographically earliest sequence of nonnegative integers with as many distinct values as possible such that for any n >= 0, a(rev(n)) = a(n) (where rev(n) = A030101(n) corresponds to the binary reversal of n).

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%I A340717 #11 Jan 22 2021 14:18:42
%S A340717 0,1,1,2,1,3,2,4,1,5,3,6,2,6,4,7,1,8,5,9,3,10,6,11,2,9,6,12,4,11,7,13,
%T A340717 1,14,8,15,5,16,9,17,3,16,10,18,6,19,11,20,2,15,9,21,6,18,12,22,4,17,
%U A340717 11,22,7,20,13,23,1,24,14,25,8,26,15,27,5,28,16
%N A340717 Lexicographically earliest sequence of nonnegative integers with as many distinct values as possible such that for any n >= 0, a(rev(n)) = a(n) (where rev(n) = A030101(n) corresponds to the binary reversal of n).
%C A340717 The condition "with as many distinct values as possible" means here that for any distinct m and n, provided the orbits of m and n under the map x -> rev(x) do not merge, then a(m) <> a(n).
%H A340717 Rémy Sigrist, <a href="/A340717/b340717.txt">Table of n, a(n) for n = 0..8191</a>
%H A340717 Rémy Sigrist, <a href="/A340717/a340717.png">Colored scatterplot of the first 2^16 terms</a> (where the color is function of A007814(n), the 2-adic valuation of n)
%H A340717 Rémy Sigrist, <a href="/A340717/a340717.gp.txt">PARI program for A340717</a>
%F A340717 a(2*n) = a(n).
%F A340717 a(n) = 1 iff n is a power of 2.
%F A340717 a(n) = 2 iff n belongs to A007283.
%F A340717 a(n) = 3 iff n belongs to A020714.
%F A340717 a(n) = 4 iff n belongs to A005009.
%F A340717 a(n) = 5 iff n belongs to A005010.
%F A340717 a(A340718(n)) = n (and this is the first occurrence of n in the sequence).
%e A340717 The first terms, alongside rev(n), are:
%e A340717   n   a(n)  rev(n)
%e A340717   --  ----  ------
%e A340717    0     0       0
%e A340717    1     1       1
%e A340717    2     1       1
%e A340717    3     2       3
%e A340717    4     1       1
%e A340717    5     3       5
%e A340717    6     2       3
%e A340717    7     4       7
%e A340717    8     1       1
%e A340717    9     5       9
%e A340717   10     3       5
%e A340717   11     6      13
%e A340717   12     2       3
%e A340717   13     6      11
%e A340717   14     4       7
%e A340717   15     7      15
%o A340717 (PARI) See Links section.
%Y A340717 See A340716 for similar sequences.
%Y A340717 Cf. A000079, A005009, A005010, A007283, A007814, A020714, A030101, A340718.
%K A340717 nonn,look,base
%O A340717 0,4
%A A340717 _Rémy Sigrist_, Jan 17 2021