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 A185586 #28 Feb 16 2025 08:33:13 %S A185586 2,1,6,4,18,15,5,10,8,12,9,3,24,21,7,14,36,39,13,26,28,35,25,30,27,33, %T A185586 11,22,20,16,38,42,51,17,34,32,58,70,65,55,60,63,49,56,54,52,50,48,69, %U A185586 23,46,44,40,45,57,19,64,72,93,31,62,66,87,29,141,47,94,92,100 %N A185586 EKG sequence (A064413) written clockwise as a square spiral and read counterclockwise. %C A185586 A permutation of the natural numbers. %C A185586 The subsequence of primes (A000040) begins: 2, 5, 3, 7, 13, 11, 17, 23, 19, 31, 29, 47, 43, 41, 37, 53, ... %H A185586 Alois P. Heinz, <a href="/A185586/b185586.txt">Table of n, a(n) for n = 1..10000</a> %H A185586 J. C. Lagarias, E. M. Rains and N. J. A. Sloane, <a href="http://arXiv.org/abs/math.NT/0204011">The EKG sequence</a>, arXiv:math/0204011 [math.NT], 2002. %H A185586 J. C. Lagarias, E. M. Rains and N. J. A. Sloane, <a href="http://www.emis.de/journals/EM/expmath/volumes/11/11.3/Lagarias437_446.pdf">The EKG Sequence</a>, Exper. Math. 11 (2002), 437-446. %H A185586 I. Peterson, <a href="http://www.maa.org/mathland/mathtrek_04_08_02.html">The EKG Sequence</a> %H A185586 Eric Weisstein's World of Mathematics, <a href="https://mathworld.wolfram.com/EKGSequence.html">EKG Sequence</a> %H A185586 <a href="/index/Ed#EKG">Index entries for sequences related to EKG sequence</a> %H A185586 <a href="/index/Per#IntegerPermutation">Index entries for sequences that are permutations of the natural numbers</a> %e A185586 1,2,4,6,3,9,12,8,10,5,15,18,... are written clockwise as a square spiral, then read counterclockwise: 2,1,6,4,18,15,5,10,8,12,9,3,... %e A185586 The square spiral begins: %e A185586 . %e A185586 33--27--30--25--35--28 %e A185586 | | %e A185586 11 12---8--10---5 26 %e A185586 | | | | %e A185586 22 9 1---2 15 13 %e A185586 | | | | | %e A185586 20 3---6---4 18 39 %e A185586 | | | %e A185586 16--24--21---7--14 36 %e A185586 | %e A185586 38--42--51--17--34--32 %Y A185586 Cf. A064413. %K A185586 nonn,look %O A185586 1,1 %A A185586 _Paul Curtz_, Feb 04 2011