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A143327
Table T(n,k) by antidiagonals. T(n,k) is the number of primitive (=aperiodic) k-ary words (n,k >= 1) 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.
12
1, 1, 1, 1, 2, 1, 1, 3, 5, 1, 1, 4, 11, 11, 1, 1, 5, 19, 35, 26, 1, 1, 6, 29, 79, 115, 53, 1, 1, 7, 41, 149, 334, 347, 116, 1, 1, 8, 55, 251, 773, 1339, 1075, 236, 1, 1, 9, 71, 391, 1546, 3869, 5434, 3235, 488, 1, 1, 10, 89, 575, 2791, 9281, 19493, 21754, 9787, 983, 1, 1, 11
OFFSET
1,5
COMMENTS
The coefficients of the polynomial of row n are given by the n-th row of triangle A134541; for example row 4 has polynomial -1+k^2+k^3.
FORMULA
T(n,k) = Sum_{j=1..n} Sum_{d|j} k^(d-1) * mu(j/d).
T(n,k) = Sum_{j=1..n} A143325(j,k).
T(n,k) = A143326(n,k) / k.
EXAMPLE
T(3,3) = 11, because 11 words of length <=3 over 3-letter alphabet {a,b,c} are primitive and earlier than others derived by cyclic shifts of the alphabet: a, ab, ac, aab, aac, aba, abb, abc, aca, acb, acc.
Table begins:
1, 1, 1, 1, 1, 1, 1, 1, ...
1, 2, 3, 4, 5, 6, 7, 8, ...
1, 5, 11, 19, 29, 41, 55, 71, ...
1, 11, 35, 79, 149, 251, 391, 575, ...
1, 26, 115, 334, 773, 1546, 2791, 4670, ...
1, 53, 347, 1339, 3869, 9281, 19543, 37367, ...
1, 116, 1075, 5434, 19493, 55936, 137191, 299510, ...
1, 236, 3235, 21754, 97493, 335656, 960391, 2396150, ...
MAPLE
with(numtheory):
f1:= proc (n) option remember; unapply(k^(n-1)
-add(f1(d)(k), d=divisors(n) minus {n}), k)
end:
g1:= proc(n) option remember; unapply(add(f1(j)(x), j=1..n), x) end:
T:= (n, k)-> g1(n)(k):
seq(seq(T(n, 1+d-n), n=1..d), d=1..12);
MATHEMATICA
t[n_, k_] := Sum[k^(d-1)*MoebiusMu[j/d], {j, 1, n}, {d, Divisors[j]}]; Table[t[n-k+1, k], {n, 1, 12}, {k, n, 1, -1}] // Flatten (* Jean-François Alcover, Dec 13 2013 *)
CROSSREFS
Rows n=1-4 give: A000012, A000027, A028387, A003777.
Main diagonal gives A320095.
Sequence in context: A049513 A121207 A097084 * A094954 A083064 A204057
KEYWORD
nonn,tabl
AUTHOR
Alois P. Heinz, Aug 07 2008
STATUS
approved