A137893 Fixed point of the morphism 0->100, 1->101, starting from a(1) = 1.

1, 0, 1, 1, 0, 0, 1, 0, 1, 1, 0, 1, 1, 0, 0, 1, 0, 0, 1, 0, 1, 1, 0, 0, 1, 0, 1, 1, 0, 1, 1, 0, 0, 1, 0, 1, 1, 0, 1, 1, 0, 0, 1, 0, 0, 1, 0, 1, 1, 0, 0, 1, 0, 0, 1, 0, 1, 1, 0, 0, 1, 0, 1, 1, 0, 1, 1, 0, 0, 1, 0, 0, 1, 0, 1, 1, 0, 0, 1, 0, 1, 1, 0, 1, 1, 0, 0, 1, 0, 1, 1, 0, 1, 1, 0, 0, 1, 0, 0, 1, 0, 1, 1, 0, 0

Offset: 1

Author

Joel Reyes Noche (joel.noche(AT)up.edu.ph), Apr 30 2008

Keywords

• easy
• nonn

Comments

Similar to A080846, but with the 1's and 0's interchanged.

A generalized choral sequence c(3n+r_0)=0, c(3n+r_1)=1, c(3n+r_c)=c(n), with r_0=1, r_1=0, and r_c=2. [From Joel Reyes Noche (joel.noche(AT)up.edu.ph), Jul 09 2009]

References

• J. R. Noche, Generalized Choral Sequences, Matimyas Matematika, 31(2008), 25-28. [From Joel Reyes Noche (joel.noche(AT)up.edu.ph), Jul 09 2009]

Links

• Michael De Vlieger, Table of n, a(n) for n = 1..6561

Crossrefs

Cf. A080846 (complement), A060236 (as 1,2), A343785 (as +-1).

Cf. A026179 (indices of 0's except n=1), A189674 (partial sums).

Programs

Mathematica

Flatten[Nest[#/.{0->{1,0,0},1->{1,0,1}}&,1,5]] (* Harvey P. Dale, Jul 29 2015 *)

PARI

a(n) = my(r); until(r,[n,r]=divrem(n,3)); 2-r; \\ Kevin Ryde, Nov 09 2021