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%I #15 May 11 2020 15:15:59
%S 8,9,2,1,6,7,22,23,24,25,10,11,12,3,4,5,18,19,20,21,44,45,46,47,48,49,
%T 26,27,28,29,30,13,14,15,16,17,38,39,40,41,42,43,74,75,76,77,78,79,80,
%U 81,50,51,52,53,54,55,56,31,32,33,34,35,36,37,66,67,68,69
%N a(n) is the number immediately above n in a clockwise square spiral of the positive integers with the first step to the right.
%C Equivalently the number immediately below n in a counterclockwise spiral of the positive integers with the first step to the right.
%C This is a permutation of the positive integers. A334752 is the inverse permutation.
%H Peter Kagey, <a href="/A334751/b334751.txt">Table of n, a(n) for n = 1..10000</a>
%H <a href="/index/Per#IntegerPermutation">Index entries for sequences that are permutations of the natural numbers</a>
%e For n = 1, a(1) = 8 because 8 is immediately above one in the clockwise square spiral with first step to the right:
%e 21--22--23--24--25--26
%e | |
%e 20 7---8---9---10 27
%e | | | |
%e 19 6 1---2 11 28
%e | | | | |
%e 18 5---4---3 12 29
%e | | |
%e 17--16--15--14--13 30
%e |
%e 36--35--34--33--32--31
%Y Cf. A068225 (right), A068226 (left), A334752 (below).
%Y Cf. A174344 (x-coordinate), A268038 (y-coordinate).
%K nonn
%O 1,1
%A _Peter Kagey_, May 10 2020
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