A320094 Number of primitive (=aperiodic) 10-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.
1, 10, 109, 1099, 11098, 110989, 1110988, 11109988, 111109888, 1111099879, 11111099878, 111110998888, 1111110998887, 11111109998878, 111111109988779, 1111111099988779, 11111111099988778, 111111110999888878, 1111111110999888877, 11111111109999887887
Offset: 1
Keywords
Links
- Alois P. Heinz, Table of n, a(n) for n = 1..1000
Programs
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Maple
b:= n-> add(`if`(d=n, 10^(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);
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PARI
a(n) = sum(j=1, n, sumdiv(j, d, 10^(d-1)*moebius(j/d))); \\ Michel Marcus, Dec 11 2020
Formula
a(n) = Sum_{j=1..n} Sum_{d|j} 10^(d-1) * mu(j/d).
a(n) = A143327(n,10).
a(n) = Sum_{j=1..n} A143325(j,10).
a(n) = A143326(n,10) / 10.
G.f.: (1/(1 - x)) * Sum_{k>=1} mu(k) * x^k / (1 - 10*x^k). - Ilya Gutkovskiy, Dec 11 2020