%I #29 Jan 31 2019 08:22:45

%S 0,1,-2,-1,-4,-3,-6,-5,8,9,6,7,4,5,2,3,16,17,14,15,12,13,10,11,24,25,

%T 22,23,20,21,18,19,-32,-31,-34,-33,-36,-35,-38,-37,-24,-23,-26,-25,

%U -28,-27,-30,-29,-16,-15,-18,-17,-20,-19,-22,-21,-8,-7,-10,-9,-12,-11,-14,-13,-64,-63,-66,-65,-68,-67,-70,-69

%N Lexicographical ordering of pure imaginary integers in the base (-1+i) numeral system.

%C For ordering of pure real integers in same system see A073791.

%C All integers appear in this sequence.

%H Andrey Zabolotskiy, <a href="/A320283/b320283.txt">Table of n, a(n) for n = 0..8191</a> (terms up to 255 from Andreas K. Badea)

%H Solomon I. Khmelnik, <a href="http://lib.izdatelstwo.com/Papers2/s4.djvu">Specialized Digital Computer for Operations with Complex Numbers</a>, Questions of Radio Electronics, 12 (1964), 60-82 [in Russian].

%H W. J. Penney, <a href="https://www.nsa.gov/Portals/70/documents/news-features/declassified-documents/tech-journals/a-binary-system.pdf">A "binary" system for complex numbers</a>, NSA Technical Journal, Vol. X, No. 2 (1965), 13-15.

%H W. J. Penney, <a href="https://doi.org/10.1145/321264.321274">A "binary" system for complex numbers</a>, JACM 12 (1965), 247-248.

%F From _Andrey Zabolotskiy_, Jan 31 2019: (Start)

%F a(n) = A073791(2*n)/2.

%F a(n) = -a(4*n)/4.

%F a(n) = -4*a(floor(n/4)) + a(n mod 4). (End)

%Y Cf. A066321, A256441, A073791.

%K sign,easy

%O 0,3

%A _Andreas K. Badea_, Oct 09 2018