login

Year-end appeal: Please make a donation to the OEIS Foundation to support ongoing development and maintenance of the OEIS. We are now in our 61st year, we have over 378,000 sequences, and we’ve reached 11,000 citations (which often say “discovered thanks to the OEIS”).

A162289
a(n) = 1 if n is relatively prime to 30 else 0.
1
1, 0, 0, 0, 0, 0, 1, 0, 0, 0, 1, 0, 1, 0, 0, 0, 1, 0, 1, 0, 0, 0, 1, 0, 0, 0, 0, 0, 1, 0, 1, 0, 0, 0, 0, 0, 1, 0, 0, 0, 1, 0, 1, 0, 0, 0, 1, 0, 1, 0, 0, 0, 1, 0, 0, 0, 0, 0, 1, 0, 1, 0, 0, 0, 0, 0, 1, 0, 0, 0, 1, 0, 1, 0, 0, 0, 1, 0, 1, 0, 0, 0, 1, 0, 0, 0, 0, 0, 1, 0, 1, 0, 0, 0, 0, 0, 1, 0, 0, 0, 1, 0, 1, 0, 0
OFFSET
1,1
FORMULA
Euler transform of length 30 sequence [0, 0, 0, 0, 0, 1, 0, 0, 0, 1, 0, 0, 0, 0, 0, 0, 0, 0, 0, -1, 0, 0, 0, -1, 0, 0, 0, 0, 0, 1].
Moebius transform is length 30 sequence [1, -1, -1, 0, -1, 1, 0, 0, 0, 1, 0, 0, 0, 0, 1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, -1].
a(n) is multiplicative with a(2^e) = a(3^e) = a(5^e) = 0^e, a(p^e) = 1 if p>5.
a(n) = a(n + 30) = a(-n) for all n in Z.
G.f.: x * (1 + x^6) * (1 + x^10) * (1 + x^12) / (1 - x^30).
Dirichlet g.f.: zeta(s)*(1-1/2^s)*(1-1/3^s)*(1-1/5^s). - R. J. Mathar, Jun 01 2011
Asymptotic mean: lim_{n->oo} (1/n) * Sum_{k=1..n} = 4/15. - Amiram Eldar, Dec 06 2020
EXAMPLE
G.f. = x + x^7 + x^11 + x^13 + x^17 + x^19 + x^23 + x^29 + x^31 + x^37 + ...
MATHEMATICA
Boole[CoprimeQ[Range[110], 30]] (* Harvey P. Dale, Jul 11 2017 *)
PROG
(PARI) {a(n) = 1 == gcd(30, n)};
(PARI) x='x+O('x^100); Vec(x*(1+x^6)*(1+x^10)*(1+x^12)/(1-x^30)) \\ G. C. Greubel, Sep 25 2018
(Magma) m:=100; R<x>:=PowerSeriesRing(Integers(), m); Coefficients(R!(x*(1+x^6)*(1+x^10)*(1+x^12)/(1-x^30))); // G. C. Greubel, Sep 25 2018
CROSSREFS
Sequence in context: A288711 A347312 A089010 * A373139 A122276 A352679
KEYWORD
nonn,mult
AUTHOR
Michael Somos, Jun 29 2009
STATUS
approved