This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.
%I A163535 #16 Jul 06 2025 12:40:08 %S A163535 1,1,0,3,3,0,1,1,1,1,1,2,3,3,2,1,1,1,1,1,0,3,3,0,1,1,0,3,3,0,1,1,0,3, %T A163535 3,3,3,3,2,1,1,2,3,3,3,3,3,0,1,1,0,3,3,0,1,1,0,3,3,0,1,1,1,1,1,2,3,3, %U A163535 2,1,1,1,1,1,0,3,3,0,1,1,1,1,1,2,3,3,2,1,1,1,1,1,0,3,3,0,1,1,1,1,1,2 %N A163535 The absolute direction (0=east, 1=south, 2=west, 3=north) of the Peano curve A163336 at point n. %C A163535 Taking every ninth term gives the same sequence: (and similarly for all higher powers of 9 as well): a(n) = a(9*n). %H A163535 Antti Karttunen, <a href="/A163535/b163535.txt">Table of n, a(n) for n = 1..6561</a> %F A163535 a(n) = A010873(A163532(n)+A163533(n)+abs(A163532(n))+3). %F A163535 a(n) = A004442(A163534(n)). %o A163535 (Scheme) (define (A163535 n) (modulo (+ 3 (A163532 n) (A163533 n) (abs (A163532 n))) 4)) %Y A163535 Cf. A163534 (transposed), A163537 (turn). %K A163535 nonn %O A163535 1,4 %A A163535 _Antti Karttunen_, Aug 01 2009 %E A163535 Name corrected by _Kevin Ryde_, Aug 29 2020