0,1

Least significant bit of n, lsb(n).

Also decimal expansion of 1/99.

a(n) = ABS(A134451(n)). - Reinhard Zumkeller (reinhard.zumkeller(AT)gmail.com), Oct 27 2007

Characteristic function of odd numbers: a(A005408(n))=1, a(A005843(n))=0. [From Reinhard Zumkeller (reinhard.zumkeller(AT)gmail.com), Sep 29 2008]

A102370(n) modulo 2 . [From Philippe DELEHAM (kolotoko(AT)wanadoo.fr), Apr 04 2009]

Base b expansion of 1/(b^2-1) for any b>=2 is 0.0101... (A005563 has b^2-1). [From Rick L. Shepherd (rshepherd2(AT)hotmail.com), Sep 27 2009]

Paul Barry, A Catalan Transform and Related Transformations on Integer Sequences, Journal of Integer Sequences, Vol. 8 (2005), Article 05.4.5.

N. J. A. Sloane and Simon Plouffe, The Encyclopedia of Integer Sequences, Academic Press, 1995 (includes this sequence).

A. K. Whitford, Binet's Formula Generalized, Fib. Quart., 15 (1977), pp. 21, 24, 29.

David Wasserman, Table of n, a(n) for n = 0..1000

Index entries for sequences related to linear recurrences with constant coefficients

Index entries for characteristic functions

Y. Puri and T. Ward, Arithmetic and growth of periodic orbits, J. Integer Seqs., Vol. 4 (2001), #01.2.1.

Eric Weisstein's World of Mathematics, Dirichlet Series Generating Function

Eric Weisstein's World of Mathematics, Kronecker Symbol

Index entries for "core" sequences

a(n)={1 - (-1)^n}/2. a(n) = n mod 2.

Multiplicative with a(p^e) = p%2. - David W. Wilson (davidwwilson(AT)comcast.net), Aug 01, 2001.

G.f.: x/(1-x^2). E.g.f.: sinh(x). a(n)=n mod 2. a(n)=1/2 - (-1)^n/2. - Paul Barry (pbarry(AT)wit.ie), Mar 11 2003

a(n)=(A000051(n)-A014551(n))/2. - Mario Catalani (mario.catalani(AT)unito.it), Aug 30 2003

a(n) = ceiling((-2)^(-n-1)). - Reinhard Zumkeller (reinhard.zumkeller(AT)gmail.com), Apr 19 2005

a(n)= [sin(n*Pi/2)]^2 = [cos(n*Pi/2 +/- Pi/2)]^2 with n>=0. - Paolo P. Lava (ppl(AT)spl.at), Sep 20 2006

A000035 := n->n mod 2;

[ seq(i mod 2, i=0..100) ];

Nest[Flatten[ # /. {0 -> {0, 1}, 1 -> {0, 1}}] &, {0}, 7] (from Robert G. Wilson v Mar 05 2005)

Nest[ Flatten[ # /. {0 -> {0, 1, 0}}] &, {0}, 5] (* Robert G. Wilson v Sep 01 2005 *)

CellularAutomaton[50, {{0, 1}, 0}, 104, {All, {0}}] // Flatten [From Zerinvary Lajos (zerinvarylajos(AT)yahoo.com), Jul 08 2009]

(PARI) a(n)=n%2

See link in A140080 for Fortran program.

Ones complement of A059841. Cf. A053644 for most significant bit.

This is Guy Steele's sequence GS(1, 2) (see A135416).

Sequence in context: A112416 A061265 A125122 this_sequence A131734 A134452 A071029

Adjacent sequences: A000032 A000033 A000034 this_sequence A000036 A000037 A000038

core,easy,nonn,nice,mult

N. J. A. Sloane (njas(AT)research.att.com).