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A280237 Period length 8 sequence [0, 1, 0, 1, -1, 1, 0, 1, ...]. 1
0, 1, 0, 1, -1, 1, 0, 1, 0, 1, 0, 1, -1, 1, 0, 1, 0, 1, 0, 1, -1, 1, 0, 1, 0, 1, 0, 1, -1, 1, 0, 1, 0, 1, 0, 1, -1, 1, 0, 1, 0, 1, 0, 1, -1, 1, 0, 1, 0, 1, 0, 1, -1, 1, 0, 1, 0, 1, 0, 1, -1, 1, 0, 1, 0, 1, 0, 1, -1, 1, 0, 1, 0, 1, 0, 1, -1, 1, 0, 1, 0, 1, 0, 1 (list; graph; refs; listen; history; text; internal format)
OFFSET

0,1

LINKS

Table of n, a(n) for n=0..83.

Index entries for linear recurrences with constant coefficients, signature (0,0,0,0,0,0,0,1).

FORMULA

Euler transform of length 10 sequence [0, 1, -1, 0, 1, 0, 0, 1, 0, -1].

Moebius transform is length 8 sequence [1, -1, 0, -1, 0, 0, 0, 1].

a(n) is multiplicative with a(2) = 0, a(4) = -1, a(2^e) = 0 if e>2, a(p^e) = 1 if p>2.

G.f.: x / (1 - x^2) - x^4 / (1 - x^8).

G.f.: (x + x^3 - x^4 + x^5 + x^7) / (1 - x^8).

G.f.: x * (1 - x^2) * (1 - x^5) * (1 - x^8) / ((1 - x^3) * (1 - x^10)).

G.f.: x / (1 - x) - x^2 / (1 - x^2) - x^4 / (1 - x^4) + x^8 / (1 - x^8).

G.f. A(x) = Sum_{k>0} F(x^k) where P(x) = x - x^2 - x^4 + x^8 = x * (1 - x^3) * (1 - x - x^4).

a(n) = a(-n) = a(n+8) for all n in Z.

a(n) = -(-1)^n * A259044(n).

a(2*n + 1) = 1. a(4*n + 2) = 0. a(8*n) = 0. a(8*n + 4) = -1.

EXAMPLE

G.f. = x + x^3 - x^4 + x^5 + x^7 + x^9 + x^11 - x^12 + x^13 + x^15 + ...

MATHEMATICA

a[ n_] := Mod[n, 2] - Boole[ Mod[n, 8] == 4];

a[ n_] := {0, 1, 0, 1, -1, 1, 0, 1}[[Mod[n, 8] + 1]];

a[ n_] := SeriesCoefficient[ x / (1 - x^2) - x^4 / (1 - x^8), {x, 0, Abs@n}];

PROG

(PARI) {a(n) = n%2 - (n%8==4)};

(PARI) {a(n) = [0, 1, 0, 1, -1, 1, 0, 1][n%8 + 1]};

(PARI) {a(n) = 1 - (n%2==0) - (n%4==0) + (n%8==0)};

(PARI) {a(n) = polcoeff( x / (1 - x^2) - x^4 / (1 - x^8) + x * O(x^abs(n)), abs(n))};

CROSSREFS

Cf. A259044.

Sequence in context: A157412 A023532 A030308 * A259044 A112690 A115971

Adjacent sequences:  A280234 A280235 A280236 * A280238 A280239 A280240

KEYWORD

sign,mult,easy,changed

AUTHOR

Michael Somos, Dec 29 2016

STATUS

approved

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Last modified May 23 01:14 EDT 2018. Contains 304445 sequences. (Running on oeis4.)