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 A134452 #14 Feb 16 2025 08:33:06 %S A134452 0,1,0,1,0,-1,0,1,0,1,0,1,0,1,0,-1,0,-1,0,1,0,1,0,-1,0,1,0,1,0,1,0,1, %T A134452 0,1,0,1,0,1,0,1,0,-1,0,-1,0,-1,0,-1,0,1,0,-1,0,-1,0,1,0,1,0,-1,0,1,0, %U A134452 1,0,1,0,1,0,-1,0,-1,0,1,0,1,0,-1,0,1,0,1,0,1,0,1,0,1,0,1,0,1,0,1,0,-1,0,1,0,1,0,1,0,1,0,1,0,1,0,1,0,1,0,1,0,1,0,1,0,1,0 %N A134452 Balanced ternary digital root of n. %C A134452 a(A005843(n))=0; a(A134453(n))=-1; a(A134454(n))=1; abs(a(A005408(n)))=1; %C A134452 abs(a(n)) = A000035(n). %D A134452 D. E. Knuth, The Art of Computer Programming, Addison-Wesley, Reading, MA, Vol 2, pp 173-175. %H A134452 R. Zumkeller, <a href="/A134452/b134452.txt">Table of n, a(n) for n = 0..10000</a> %H A134452 Eric Weisstein's World of Mathematics, <a href="https://mathworld.wolfram.com/DigitalRoot.html">Digital Root</a> %H A134452 Wikipedia, <a href="http://en.wikipedia.org/wiki/Balanced_ternary">Balanced Ternary</a> %F A134452 a(n) = f(n) where f(n) = if n<-1 then f(-A065363(-n)) else (if n>1 then f(A065363(n)) else n). %e A134452 42 == '+---0' --> +1-1-2-1+0=-2 == '-+' --> -1+1=0; %e A134452 43 == '+---+' --> +1-1-2-1+1=-1; %Y A134452 Cf. A065363, A134453, A134454, A005843, A005408, A000035. %Y A134452 Cf. A134451. %K A134452 sign,base %O A134452 0,1 %A A134452 _Reinhard Zumkeller_, Oct 27 2007