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A243697
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Number of meta-Sylvester classes of 3-multiparking functions of length n.
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3
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1, 1, 5, 44, 551, 8919, 176634, 4130208, 111222029, 3386390387, 114938069867, 4300300340056, 175745611297708, 7786523264786248, 371635506967477674, 19004259907335519264, 1036363461255181310601, 60024383356961580954471, 3679068900776781256346115
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OFFSET
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0,3
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COMMENTS
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See Novelli-Thibon (2014) for precise definition.
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LINKS
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FORMULA
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G.f.: 1/(1-x) = Sum_{n>=0} a(n) * x^n*(1-x)^n / Product_{k=1..n} (1 + 3*k*x). - Paul D. Hanna, Jun 14 2014
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MATHEMATICA
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a[n_] := a[n] = If[n<0, 0, Coefficient[1/(1 - x + x O[x]^n) - Sum[a[k] x^k (1-x)^k/Product[1 + 3j x + x O[x]^n, {j, 0, k}], {k, 1, n-1}], x, n]];
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PROG
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(PARI) {a(n)=if(n<0, 0, polcoeff(1/(1-x+x*O(x^n)) - sum(k=1, n-1, a(k)*x^k*(1-x)^k/prod(j=0, k, 1+3*j*x+x*O(x^n))), n))}
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CROSSREFS
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KEYWORD
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nonn
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AUTHOR
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EXTENSIONS
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STATUS
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approved
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