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.
%I A080543 #12 Apr 11 2022 12:07:53
%S A080543 1,2,3,4,5,6,7,8,12,9,13,10,14,11,15,16,20,24,28,17,21,25,29,18,22,26,
%T A080543 30,19,23,27,31,32,36,40,44,48,52,56,60,33,37,41,45,49,53,57,61,34,38,
%U A080543 42,46,50,54,58,62,35,39,43,47,51,55,59,63,64,68,72,76,80,84,88,92,96
%N A080543 In binary representation: keep the first digit and rotate left the others twice.
%C A080543 a(n) = A080541(A080541(n)); permutation of natural numbers with inverse = A080544: A080544(a(n)) = a(A080544(n)) = n.
%H A080543 Ivan Neretin, <a href="/A080543/b080543.txt">Table of n, a(n) for n = 1..8192</a>
%H A080543 <a href="/index/Per#IntegerPermutation">Index entries for sequences that are permutations of the natural numbers</a>
%e A080543 a(20) = a('10100') = '100001' = 17; a(24) = a('11000') = '10010' = 18.
%t A080543 Table[FromDigits[Prepend[RotateLeft[Rest[IntegerDigits[n, 2]], 2], 1], 2], {n, 72}] (* _Ivan Neretin_, Aug 30 2015 *)
%Y A080543 Cf. A080541, A080544.
%K A080543 nonn,base
%O A080543 1,2
%A A080543 _Reinhard Zumkeller_, Feb 20 2003