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!)
A038069 Product_{k>=1} ((1 + x^k)^a(k)) = 1 + 4x. 7
4, -6, 20, -66, 204, -670, 2340, -8226, 29120, -104754, 381300, -1398410, 5162220, -19172790, 71582716, -268439586, 1010580540, -3817733920, 14467258260, -54975633702, 209430785460, -799644629550, 3059510616420 (list; graph; refs; listen; history; text; internal format)
OFFSET
1,1
LINKS
N. J. A. Sloane, Weigh transform
FORMULA
Dirichlet convolution of A038065 with characteristic function of powers of 2.
a(n) = (1/n)*(-(-4)^n + Sum_{d<n and d|n} (-1)^(n/d)*d*a(d)). - Seiichi Manyama, Jun 23 2018
CROSSREFS
Sequence in context: A088015 A027377 A048789 * A274425 A019147 A026722
KEYWORD
sign
AUTHOR
Christian G. Bower, Jan 04 1999
STATUS
approved

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 March 19 03:33 EDT 2024. Contains 370952 sequences. (Running on oeis4.)