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 A366626 #11 Oct 15 2023 02:46:24
%S A366626 5,2,1,4,7,10,3,6,9,12,11,8,17,14,13,16,19,22,15,18,21,24,23,20,29,26,
%T A366626 25,28,31,34,27,30,33,36,35,32,41,38,37,40,43,46,39,42,45,48,47,44,53,
%U A366626 50,49,52,55,58,51,54,57,60,59,56,65,62,61,64,67,70,63,66,69,72,71
%N A366626 Group the natural numbers into blocks of size 2: [1,2], [3,4], ... and then reverse the order of the numbers within each block. Then group and reverse for each block size up to 4.
%C A366626 Row 4 of the array in A007062.
%H A366626 <a href="/index/Rec#order_12">Index entries for linear recurrences with constant coefficients</a>, signature (2,-2,2,-2,2,-2,2,-2,2,-2,2,-1).
%F A366626 a(n) = A366619(A113778(n)).
%e A366626 Group natural numbers into blocks of 2: [1, 2], [3, 4], [5, 6], [7, 8], ...
%e A366626 Reverse the order in each block: [2, 1], [4, 3], [6, 5], [8, 7], ...
%e A366626 Group the remaining sequence into blocks of 3: [2, 1, 4], [3, 6, 5], ...
%e A366626 Reverse the order in each block: [4, 1, 2], [5, 6, 3], ...
%e A366626 Group the remaining sequence into blocks of 4: [4, 1, 2, 5], [6, 3, 10, 7],
%e A366626 Reverse the order in each block to get a(n): 5, 2, 1, 4, 7, 10, 3, 6, ...
%t A366626 Table[1 + Mod[n + 1, 2] + 2 Floor[3 Floor[((1 + 4 Floor[(n - 1)/4] + Mod[-n, 4]) - 1)/3]/2 + Mod[-(1 + 4 Floor[(n - 1)/4] + Mod[-n, 4]), 3]/2], {n, 100}]
%Y A366626 Cf. A007062, A113778, A366619.
%K A366626 nonn,easy
%O A366626 1,1
%A A366626 _Wesley Ivan Hurt_, Oct 14 2023