A123594 Unique sequence of 0's and 1's which are either repeated or not repeated with the following property: when the sequence is 'coded' in writing down a 1 when an element is repeated and a 0 when it is not repeated and by putting the initial element in front of the sequence thus obtained, the above sequence appears.

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

Offset

1,1

Links

Vantieghem Emmanuel, Nov 14 2006, Table of n, a(n) for n = 1..620

Formula

a(n+2) = A000002(n)-1. - Danny Rorabaugh, Mar 04 2015

Mathematica

a = {1, 1, 0}; i = 2; Label[be]; i += 1; t = Part[a, i]; If[t == 0, b = {a, 1 - Part[a, Length[a]]}; a := Flatten[b], b = {a, Part[a, Length[a]]}; a := Flatten[b]; b = {a, 1 - Part[a, Length[a]]}; a := Flatten[b]]; If[i > 1000, Print[a], Goto[be]]

Crossrefs

Cf. A000002.

Sequence in context: A353816 A141727 A298952 * A286801 A189091 A344863

Adjacent sequences: A123591 A123592 A123593 * A123595 A123596 A123597

Keyword

easy,nonn

Author

Emmanuel Vantieghem, Nov 14 2006

Status

approved