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Number of irreducible multiple zeta values at weight n.
8

%I #87 Jul 22 2020 05:24:21

%S 0,1,1,0,1,0,1,1,1,1,2,2,3,3,4,5,7,8,11,13,17,21,28,34,45,56,73,92,

%T 120,151,197,250,324,414,537,687,892,1145,1484,1911,2479,3196,4148,

%U 5359,6954,9000,11687,15140,19672,25516,33166,43065,56010,72784,94716,123185

%N Number of irreducible multiple zeta values at weight n.

%C n * a(n) is the Möbius transform of the Perrin sequence A001608.

%C Number of unlabeled (i.e., defined up to a rotation) maximal independent sets of the n-cycle graph having n isomorphic representatives. - Jean-Luc Marichal (jean-luc.marichal(AT)uni.lu), Jan 24 2007

%H Danny Rorabaugh, <a href="/A113788/b113788.txt">Table of n, a(n) for n = 1..8000</a>

%H Kam Cheong Au, <a href="https://arxiv.org/abs/2007.03957">Evaluation of one-dimensional polylogarithmic integral, with applications to infinite series</a>, arXiv:2007.03957 [math.NT], 2020. See 1st line of Table 1 (p. 6).

%H R. Bisdorff and J.-L. Marichal, <a href="https://arxiv.org/abs/math/0701647">Counting non-isomorphic maximal independent sets of the n-cycle graph</a>, arXiv:0701647 [math.CO], 2007-2008.

%H R. Bisdorff and J.-L. Marichal, <a href="https://cs.uwaterloo.ca/journals/JIS/VOL11/Marichal/marichal.html">Counting non-isomorphic maximal independent sets of the n-cycle graph</a>, JIS 11 (2008), #08.5.7.

%H D. J. Broadhurst and D. Kreimer, <a href="http://arXiv.org/abs/hep-th/9609128">Association of multiple zeta values with positive knots via Feynman diagrams up to 9 loops</a>, UTAS-PHYS-96-44; arXiv:hep-th/9609128, 1996.

%H D. J. Broadhurst and D. Kreimer, <a href="http://dx.doi.org/10.1016/S0370-2693(96)01623-1">Associated multiple zeta values with positive knots via Feynman diagrams up to 9 knots</a>, Phys. Lett B, 393 (1997), 403-412.

%H M. Waldschmidt, <a href="http://www.math.jussieu.fr/~miw/articles/pdf/MZV2011IMSc.pdf">Lectures on Multiple Zeta Values</a>, IMSC 2011.

%F a(n) = (1/n) * Sum_{d|n} mu(n/d)*Perrin(d), where Perrin(d) = A001608 starting with 0, 2, 3, ... .

%F a(n) = Sum_{d|n} mu(n/d)*A127687(d) = (1/n) * Sum_{d|n} mu(n/d)*A001608(d). - Jean-Luc Marichal (jean-luc.marichal(AT)uni.lu), Jan 24 2007

%F For p an odd prime, a(p) = Sum_{i=0..floor((p-3)/6)} (A(i)+B(i)-1)!/(A(i)!*B(i)!), where A(i) = (p-3)/2 - 3*i, and B(i) = 1 + 2*i. - _Richard Turk_, Sep 08 2015

%F a(n) ~ A060006^n / n. - _Vaclav Kotesovec_, Oct 09 2019

%p A113788 := proc(n::integer)

%p local resul,d;

%p resul :=0;

%p for d from 1 to n do

%p if n mod d = 0 then

%p resul := resul +numtheory[mobius](n/d)*A001608(d);

%p fi;

%p od:

%p RETURN(resul/n);

%p end: # _R. J. Mathar_, Apr 25 2006

%t (* p = A001608 *) p[n_] := p[n] = p[n-2] + p[n-3]; p[0] = 3; p[1] = 0; p[2] = 2; a[n_] := (1/n)*Sum[MoebiusMu[n/d]*p[d], {d, Divisors[n]}]; Table[a[n], {n, 1, 56}] (* _Jean-François Alcover_, Jul 16 2012, from first formula *)

%o (Sage)

%o z = PowerSeriesRing(ZZ, 'z').gen().O(30)

%o r = (1 - (z**2 + z**3))

%o F = -z*r.derivative()/r

%o [sum(moebius(n//d)*F[d] for d in divisors(n))//n for n in range(1, 24)] # _F. Chapoton_, Apr 24 2020

%Y Cf. A001608, A127687, A125951.

%K nonn,easy

%O 1,11

%A _R. J. Mathar_, Jan 27 2006