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A321767 Reverse runs of nonzero digits in ternary expansion of n and convert back to decimal.

%I A321767 #11 Nov 19 2018 12:23:03
%S A321767 0,1,2,3,4,5,6,7,8,9,10,19,12,13,14,15,16,17,18,11,20,21,22,23,24,25,
%T A321767 26,27,28,55,30,37,46,57,64,73,36,31,58,39,40,41,42,43,44,45,32,59,48,
%U A321767 49,50,51,52,53,54,29,56,33,38,47,60,65,74,63,34,61,66,67
%N A321767 Reverse runs of nonzero digits in ternary expansion of n and convert back to decimal.
%C A321767 This sequence is a self-inverse permutation of nonnegative integers.
%H A321767 Rémy Sigrist, <a href="/A321767/b321767.txt">Table of n, a(n) for n = 0..19683</a>
%H A321767 Rémy Sigrist, <a href="/A321767/a321767.gp.txt">PARI program for A321767</a>
%H A321767 <a href="/index/Per#IntegerPermutation">Index entries for sequences that are permutations of the natural numbers</a>
%F A321767 a(3 * n) = 3 * a(n).
%e A321767 For n = 11111:
%e A321767 - the ternary representation of 11111 is "120020112",
%e A321767 - we have three runs of nonzero digits: "12", "2" and "112",
%e A321767 - we replace the first by the third, the third by the first and the second remains in place,
%e A321767 - the result is: "112002012",
%e A321767 - and a(11111) = 10265.
%o A321767 (PARI) See Links section.
%Y A321767 See A321726 for a similar sequence.
%K A321767 nonn,base,look
%O A321767 0,3
%A A321767 _Rémy Sigrist_, Nov 18 2018