login
The OEIS is supported by the many generous donors to the OEIS Foundation.

 

Logo
Hints
(Greetings from The On-Line Encyclopedia of Integer Sequences!)
A323407 Dirichlet inverse of A047994, unitary phi. 2

%I #5 Jan 15 2019 18:43:14

%S 1,-1,-2,-2,-4,2,-6,-2,-4,4,-10,4,-12,6,8,0,-16,4,-18,8,12,10,-22,4,

%T -8,12,-2,12,-28,-8,-30,4,20,16,24,8,-36,18,24,8,-40,-12,-42,20,16,22,

%U -46,0,-12,8,32,24,-52,2,40,12,36,28,-58,-16,-60,30,24,8,48,-20,-66,32,44,-24,-70,8,-72,36,16,36,60,-24,-78,0,8,40,-82,-24

%N Dirichlet inverse of A047994, unitary phi.

%H Antti Karttunen, <a href="/A323407/b323407.txt">Table of n, a(n) for n = 1..20000</a>

%o (PARI)

%o up_to = 65537;

%o DirInverse(v) = { my(u=vector(#v)); u[1] = (1/v[1]); for(n=2, #v, u[n] = -sumdiv(n, d, if(d<n, v[n/d]*u[d], 0))); (u) }; \\ Compute the Dirichlet inverse of the sequence given in input vector v.

%o A047994(n)=my(f=factor(n)~); prod(i=1, #f, f[1, i]^f[2, i]-1);

%o v323407 = DirInverse(vector(up_to,n,A047994(n)));

%o A323407(n) = v323407[n];

%Y Cf. A047994, A323408.

%Y Cf. also A023900.

%K sign

%O 1,3

%A _Antti Karttunen_, Jan 15 2019

Lookup | Welcome | Wiki | Register | Music | Plot 2 | Demos | Index | Browse | More | WebCam
Contribute new seq. or comment | Format | Style Sheet | Transforms | Superseeker | Recents
The OEIS Community | Maintained by The OEIS Foundation Inc.

License Agreements, Terms of Use, Privacy Policy. .

Last modified September 2 18:29 EDT 2024. Contains 375616 sequences. (Running on oeis4.)