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A368225 Irregular table of nonnegative integers read by rows: the 1's in the binary expansion of n exactly match the nonzero digits in the balanced ternary expansions of the terms in the n-th row. 4

%I #16 Dec 19 2023 16:50:03

%S 0,1,3,2,4,9,8,10,6,12,5,7,11,13,27,26,28,24,30,23,25,29,31,18,36,17,

%T 19,35,37,15,21,33,39,14,16,20,22,32,34,38,40,81,80,82,78,84,77,79,83,

%U 85,72,90,71,73,89,91,69,75,87,93,68,70,74,76,86,88,92,94

%N Irregular table of nonnegative integers read by rows: the 1's in the binary expansion of n exactly match the nonzero digits in the balanced ternary expansions of the terms in the n-th row.

%C As a flat sequence, this is a permutation of the nonnegative integers with inverse A368226 and infinitely many fixed points (see Formula section).

%C Row 0 has one term, and for n > 0, row n has A048896(n-1) terms.

%C For any n >= 0, row n ends with A005836(n+1).

%H Rémy Sigrist, <a href="/A368225/b368225.txt">Table of n, a(n) for n = 0..9841</a> (rows for n = 0..2^9-1 flattened)

%H <a href="/index/Per#IntegerPermutation">Index entries for sequences that are permutations of the natural numbers</a>

%F A343231(T(n, k)) = n.

%F a(m) = m for any m in A003462.

%e Table T(n, k) begins:

%e 0;

%e 1;

%e 3;

%e 2, 4;

%e 9;

%e 8, 10;

%e 6, 12;

%e 5, 7, 11, 13;

%e 27;

%e 26, 28;

%e 24, 30;

%e 23, 25, 29, 31;

%e 18, 36;

%e 17, 19, 35, 37;

%e 15, 21, 33, 39;

%e 14, 16, 20, 22, 32, 34, 38, 40;

%e 81;

%e ...

%o (PARI) row(n) = { my (r = [sign(n)], b = binary(n)); for (k = 2, #b, r = [3*v+b[k]|v<-r]; if (b[k], r = concat(r, [v-2|v<-r]););); Set(r); }

%Y See A368229 and A368239 for similar sequences.

%Y Cf. A003462, A005836, A048896, A343231, A353662, A368226 (inverse).

%K nonn,tabf,base

%O 0,3

%A _Rémy Sigrist_, Dec 18 2023

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Last modified August 28 05:00 EDT 2024. Contains 375477 sequences. (Running on oeis4.)