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

 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 60th year, we have over 367,000 sequences, and we’ve reached 11,000 citations (which often say “discovered thanks to the OEIS”). Other ways to Give
 Hints (Greetings from The On-Line Encyclopedia of Integer Sequences!)
 A320074 Number of length n primitive (=aperiodic or period n) 9-ary words which are earlier in lexicographic order than any other word derived by cyclic shifts of the alphabet. 4
 1, 8, 80, 720, 6560, 58960, 531440, 4782240, 43046640, 387413920, 3486784400, 31380999840, 282429536480, 2541865296880, 22876792448320, 205891127311680, 1853020188851840, 16677181656560880, 150094635296999120, 1350851717285570880, 12157665459056397280 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,2 COMMENTS Dirichlet convolution of mu(n) with 9^(n-1). LINKS Alois P. Heinz, Table of n, a(n) for n = 1..1048 FORMULA a(n) = Sum_{d|n} 9^(d-1) * mu(n/d). a(n) = 9^(n-1) - Sum_{d=1} mu(k)*x^k/(1 - 9*x^k). - Ilya Gutkovskiy, Oct 25 2018 MAPLE a:= n-> add(`if`(d=n, 9^(n-1), -a(d)), d=numtheory[divisors](n)): seq(a(n), n=1..25); CROSSREFS Column k=9 of A143325. First differences of A320093. Cf. A008683, A074650, A143324. Sequence in context: A145729 A280121 A182604 * A290874 A024101 A291181 Adjacent sequences: A320071 A320072 A320073 * A320075 A320076 A320077 KEYWORD nonn AUTHOR Alois P. Heinz, Oct 05 2018 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.

Last modified December 4 08:33 EST 2023. Contains 367558 sequences. (Running on oeis4.)