A091830 a(1)=1; a(2n)=(a(n)+1) mod 2, a(2n+1)=a(2n)+1.

1, 0, 1, 1, 2, 0, 1, 0, 1, 1, 2, 1, 2, 0, 1, 1, 2, 0, 1, 0, 1, 1, 2, 0, 1, 1, 2, 1, 2, 0, 1, 0, 1, 1, 2, 1, 2, 0, 1, 1, 2, 0, 1, 0, 1, 1, 2, 1, 2, 0, 1, 0, 1, 1, 2, 0, 1, 1, 2, 1, 2, 0, 1, 1, 2, 0, 1, 0, 1, 1, 2, 0, 1, 1, 2, 1, 2, 0, 1, 0, 1, 1, 2, 1, 2, 0, 1, 1, 2, 0, 1, 0, 1, 1, 2, 0, 1, 1, 2, 1, 2, 0, 1, 1, 2

Offset

1,5

Comments

Parity of sum(i=1,2n-1,a(i)) = parity of n.

Links

Table of n, a(n) for n=1..105.

Formula

a(2*A059010(n))=0; a(A059010(n))=1; a(2*A059009(n)+1)=2

Fixed point of morphism 0 -> 01, 1 -> 12, 2 -> 01.

Mathematica

a[1] = 1; a[n_] := a[n] = If[ EvenQ[n], Mod[ a[n/2] + 1, 2], a[n - 1] + 1]; Table[ a[n], {n, 105}] (* Robert G. Wilson v, Nov 03 2005 *)

Prog

(PARI) a(n)=if(n<2, 1, if(n%2, (a(n-1)+1), (a(n/2)+1)%2))

Crossrefs

Sequence in context: A324572 A153148 A378437 * A029427 A353506 A343380

Adjacent sequences: A091827 A091828 A091829 * A091831 A091832 A091833

Keyword

nonn

Author

Benoit Cloitre, Mar 09 2004

Extensions

Duplicate Mathematica program removed by Harvey P. Dale, May 26 2023

Status

approved