cp's OEIS Frontend

A232114 a(n) is the Manhattan distance between n and n^2 in a square spiral of positive integers with 1 at the center.

%I A232114 #13 Aug 17 2018 11:01:55
%S A232114 0,2,2,2,6,4,6,8,6,12,8,12,12,12,16,12,20,14,20,18,20,22,20,26,20,30,
%T A232114 22,30,26,30,30,30,34,30,38,30,42,32,42,36,42,40,42,44,42,48,42,52,42,
%U A232114 56,44,56,48,56,52,56,56,56,60,56,64,56,68,56,72,58,72,62,72,66
%N A232114 a(n) is the Manhattan distance between n and n^2 in a square spiral of positive integers with 1 at the center.
%C A232114 Spiral begins:
%C A232114 .
%C A232114   49  26--27--28--29--30--31
%C A232114    |   |                   |
%C A232114   48  25  10--11--12--13  32
%C A232114    |   |   |           |   |
%C A232114   47  24   9   2---3  14  33
%C A232114    |   |   |   |   |   |   |
%C A232114   46  23   8   1   4  15  34
%C A232114    |   |   |       |   |   |
%C A232114   45  22   7---6---5  16  35
%C A232114    |   |               |   |
%C A232114   44  21--20--19--18--17  36
%C A232114    |                       |
%C A232114   43--42--41--40--39--38--37
%C A232114 .
%C A232114 Numbers n such that a(n)=n: 2, 8, 12, 22, 30, 44, 56, 74, 90, 112, 132, 158, 182, 212, 240, 274, 306, 344, 380, 422, ... That is, 2 * A084263.
%Y A232114 Cf. A000290, A084263, A214526, A232113, A232115.
%K A232114 nonn
%O A232114 1,2
%A A232114 _Alex Ratushnyak_, Nov 19 2013