This site is supported by donations to The OEIS Foundation.

 Hints (Greetings from The On-Line Encyclopedia of Integer Sequences!)
 A320091 Number of primitive (=aperiodic) 7-ary words with length less than or equal to n which are earlier in lexicographic order than any other word derived by cyclic shifts of the alphabet. 3
 1, 7, 55, 391, 2791, 19543, 137191, 960391, 6725143, 47076343, 329551591, 2306861191, 16148148391, 113037041143, 791260111543, 5538820797943, 38771751367543, 271402259573191, 1899815857483639, 13298711002502839, 93090977299997143, 651636841100805895 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,2 LINKS Alois P. Heinz, Table of n, a(n) for n = 1..1184 FORMULA a(n) = Sum_{j=1..n} Sum_{d|j} 7^(d-1) * mu(j/d). a(n) = A143327(n,7). a(n) = Sum_{j=1..n} A143325(j,7). a(n) = A143326(n,7) / 7. MAPLE b:= n-> add(`if`(d=n, 7^(n-1), -b(d)), d=numtheory[divisors](n)): a:= proc(n) option remember; b(n)+`if`(n<2, 0, a(n-1)) end: seq(a(n), n=1..30); CROSSREFS Column k=7 of A143327. Partial sums of A320072. Cf. A008683, A143325, A143326. Sequence in context: A217327 A069404 A198689 * A172743 A015564 A070997 Adjacent sequences:  A320088 A320089 A320090 * A320092 A320093 A320094 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 | Recent
The OEIS Community | Maintained by The OEIS Foundation Inc.

Last modified July 24 05:21 EDT 2019. Contains 325290 sequences. (Running on oeis4.)