The OEIS mourns the passing of Jim Simons and is grateful to the Simons Foundation for its support of research in many branches of science, including the OEIS.
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!)
A349344 Dirichlet inverse of A109168, where A109168(n) = (n+A006519(n))/2, and A006519 is the highest power of 2 dividing n. 6

%I #11 Nov 21 2021 10:16:27

%S 1,-2,-2,0,-3,4,-4,0,-1,6,-6,0,-7,8,4,0,-9,2,-10,0,5,12,-12,0,-4,14,

%T -2,0,-15,-8,-16,0,7,18,6,0,-19,20,8,0,-21,-10,-22,0,3,24,-24,0,-9,8,

%U 10,0,-27,4,8,0,11,30,-30,0,-31,32,4,0,9,-14,-34,0,13,-12,-36,0,-37,38,8,0,9,-16,-40,0,-4,42,-42,0

%N Dirichlet inverse of A109168, where A109168(n) = (n+A006519(n))/2, and A006519 is the highest power of 2 dividing n.

%H Antti Karttunen, <a href="/A349344/b349344.txt">Table of n, a(n) for n = 1..20000</a>

%F a(1) = 1; a(n) = -Sum_{d|n, d < n} A109168(n/d) * a(d).

%F a(n) = A349345(n) - A109168(n).

%o (PARI)

%o up_to = 20000;

%o DirInverseCorrect(v) = { my(u=vector(#v)); u[1] = (1/v[1]); for(n=2, #v, u[n] = (-u[1]*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 A109168(n) = ((n+bitand(n, -n))\2); \\ From A109168 by _M. F. Hasler_, Oct 19 2019 (Cf. A140472).

%o v349344 = DirInverseCorrect(vector(up_to,n,A109168(n)));

%o A349344(n) = v349344[n];

%Y Cf. A109168 (A140472), A349345.

%Y Cf. also A328203, A349134, A349343, A349346, A349353.

%K sign

%O 1,2

%A _Antti Karttunen_, Nov 15 2021

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 May 20 23:09 EDT 2024. Contains 372720 sequences. (Running on oeis4.)