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The absolute direction (0=east, 1=south, 2=west, 3=north) of the Peano curve A163334 at point n.
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%I #13 Aug 29 2020 02:15:52

%S 0,0,1,2,2,1,0,0,0,0,0,3,2,2,3,0,0,0,0,0,1,2,2,1,0,0,1,2,2,1,0,0,1,2,

%T 2,2,2,2,3,0,0,3,2,2,2,2,2,1,0,0,1,2,2,1,0,0,1,2,2,1,0,0,0,0,0,3,2,2,

%U 3,0,0,0,0,0,1,2,2,1,0,0,0,0,0,3,2,2,3,0,0,0,0,0,1,2,2,1,0,0,0,0,0,3

%N The absolute direction (0=east, 1=south, 2=west, 3=north) of the Peano curve A163334 at point n.

%C Taking every ninth term gives the same sequence: (and similarly for all higher powers of 9 as well): a(n) = a(9*n).

%H Antti Karttunen, <a href="/A163534/b163534.txt">Table of n, a(n) for n = 1..59049</a>

%F a(n) = A010873(A163532(n)+A163533(n)+abs(A163533(n))+3).

%F a(n) = A004442(A163535(n)).

%o (Scheme:) (define (A163534 n) (modulo (+ 3 (A163532 n) (A163533 n) (abs (A163533 n))) 4))

%Y Cf. A163535 (transposed direction), A163536 (turn).

%K nonn

%O 1,4

%A _Antti Karttunen_, Aug 01 2009

%E Name corrected by _Kevin Ryde_, Aug 29 2020