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%I #18 Mar 07 2021 14:41:18
%S 0,3,2,1,14,15,12,13,8,11,10,9,6,7,4,5,58,57,56,59,60,63,62,61,50,49,
%T 48,51,52,55,54,53,32,35,34,33,46,47,44,45,40,43,42,41,38,39,36,37,26,
%U 25,24,27,28,31,30,29,18,17,16,19,20,23,22,21,234,235,232
%N The n-th and a(n)-th points of the Hilbert's Hamiltonian walk (A059252, A059253) are symmetrical with respect to the line X=Y.
%C In other words, a(n) is the unique k such that A059252(n) = A059253(k) and A059253(n) = A059252(k).
%C This sequence is a self-inverse permutation of the nonnegative integers.
%H Rémy Sigrist, <a href="/A342217/b342217.txt">Table of n, a(n) for n = 0..4095</a>
%H Rémy Sigrist, <a href="/A342217/a342217.gp.txt">PARI program for A342217</a>
%H <a href="/index/Per#IntegerPermutation">Index entries for sequences that are permutations of the nonnegative integers</a>
%F a(n) = n iff n belongs to A062880.
%F a(n) < 16^k for any n < 16^k.
%e The Hilbert's Hamiltonian walk (A059252, A059253) begins as follows:
%e + +-----+-----+
%e |15 |12 11 |10
%e | | |
%e +-----+ +-----+
%e 14 13 |8 9
%e |
%e +-----+ +-----+
%e |1 |2 7 |6
%e | | |
%e + +-----+-----+
%e 0 3 4 5
%e - so a(0) = 0,
%e a(1) = 3,
%e a(2) = 2,
%e a(4) = 14,
%e a(5) = 15,
%e a(7) = 13,
%e a(8) = 8,
%e a(9) = 11,
%e a(10) = 10.
%o (PARI) See Links section.
%Y See A342218 and A342224 for similar sequences.
%Y Cf. A059252, A059253, A062880.
%K nonn
%O 0,2
%A _Rémy Sigrist_, Mar 05 2021
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