A108882 Period doubling sequence starting with '1 0 1'.

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

Offset

1,1

Comments

Start with S = 1,0,1; replace S by SS and complement the last bit; iterate.

Similar to A035263 but with a different start.

Links

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

Mathematica

f[l_] := Block[{s = Flatten[{l, l}]}, s[[ -1]] = Mod[s[[ -1]] + 1, 2]; s]; Nest[f, {1, 0, 1}, 6] (* Robert G. Wilson v, Jul 16 2005 *)

Prog

s=[1 0 1]; loop s=concat(s, s); s(length(s))=(s(length(s))+1)modulo2 endloop

Crossrefs

Cf. A035263.

Sequence in context: A141212 A341347 A137893 * A369989 A284656 A168002

Adjacent sequences: A108879 A108880 A108881 * A108883 A108884 A108885

Keyword

easy,nonn

Author

Alexandre Losev, Jul 14 2005

Extensions

More terms from Robert G. Wilson v, Jul 16 2005

Status

approved