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A074650 Table T(n,k) by antidiagonals. Number of Lyndon words (aperiodic necklaces) with n beads of k colors. 17
1, 2, 0, 3, 1, 0, 4, 3, 2, 0, 5, 6, 8, 3, 0, 6, 10, 20, 18, 6, 0, 7, 15, 40, 60, 48, 9, 0, 8, 21, 70, 150, 204, 116, 18, 0, 9, 28, 112, 315, 624, 670, 312, 30, 0, 10, 36, 168, 588, 1554, 2580, 2340, 810, 56, 0, 11, 45, 240, 1008, 3360, 7735, 11160, 8160, 2184, 99, 0, 12 (list; table; graph; refs; listen; history; internal format)
OFFSET

1,2

REFERENCES

F. Bergeron, G. Labelle and P. Leroux, Combinatorial Species and Tree-Like Structures, Cambridge, 1998, pg 97 (2.3.74)

LINKS

Index entries for sequences related to Lyndon words

FORMULA

T(n,k) = (1/n) * Sum ( mu(n/d)*k^d ), d|n

T(n,k) = (k^n - Sum_{d<n,d|n} d*T(d,k)) / n - Alois P. Heinz, Mar 28 2008

EXAMPLE

1, 2,  3,   4,   5 ...

0, 1,  3,   6,  10 ...

0, 2,  8,  20,  40 ...

0, 3, 18,  60, 150 ...

0, 6, 48, 204, 624 ...

MAPLE

with (numtheory): T := proc (n, k) add(mobius(n/d)*k^d, d=divisors(n))/n end; seq (seq(T(i, d-i), i=1..d-1), d=2..12);  # Alois P. Heinz, Mar 28 2008

MATHEMATICA

max = 12; t[n_, k_] := Total[ MoebiusMu[n/#]*k^# & /@ Divisors[n]]/n; Flatten[ Table[ t[n-k+1, k], {n, 1, max}, {k, n, 1, -1}]] (* From Jean-François Alcover, Oct 18 2011, after Maple *)

PROG

(PARI) T(n, k)=sumdiv(n, d, moebius(n/d)*k^d)/n \\ Charles R Greathouse IV, Oct 18 2011

CROSSREFS

Columns 2-12: A001037, A027376, A027377, A001692, A032164, A001693, A027380, A027381, A032165, A032166, A032167.

Rows 1-4: A000027, A000217(n-1), A007290(n+1), A006011.

Diagonal: A075147.

See also A102659.

Sequence in context: A003988 A185914 A144257 * A202064 A144955 A168020

Adjacent sequences:  A074647 A074648 A074649 * A074651 A074652 A074653

KEYWORD

nonn,tabl

AUTHOR

Christian G. Bower (bowerc(AT)usa.net), Aug 28 2002

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Last modified February 17 00:09 EST 2012. Contains 205978 sequences.