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%I #10 Aug 13 2018 09:02:48
%S 1,1,2,3,4,9,11,24,28,31,94,105,114,344,375,403,427,1663,1777,1882,
%T 1976,7725,8152,8555,8930,9274,44612,46588,48470,50247,51910,251101,
%U 260375,269305,277860,286012,293737,1690300,1742210,1792457,1840927
%N Square spiral sequence: numbers are placed in a square spiral, a(1)=1, a(n) is found as the sum of the row (in the previous direction) a(n-1) is in.
%H F. M. van Lamoen, <a href="http://home.wxs.nl/~lamoen/wiskunde/spiral.htm">Spiral recurrence</a>.
%e The initial part of the square spiral sequence is
%e .
%e 344-114
%e |
%e 4---3---2 105
%e | | |
%e 9 1---1 94
%e | |
%e 11--24--28--31
%Y Cf. A063177, A063178.
%K nonn
%O 1,3
%A _Floor van Lamoen_, Jul 09 2001