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 A006936 Moebius transform of numbers of preferential arrangements. 2
 0, 1, 0, 2, 12, 74, 538, 4682, 47280, 545832, 7087186, 102247562, 1622632020, 28091567594, 526858343698, 10641342970366, 230283190930560, 5315654681981354, 130370767028589528, 3385534663256845322 (list; graph; refs; listen; history; text; internal format)
 OFFSET 0,4 COMMENTS Moebius transform of A000670(n-1)=[1,1,3,13,75,...] is a(n)=[1,0,2,12,74,...]. - Michael Somos, Mar 04 2004 LINKS G. C. Greubel, Table of n, a(n) for n = 0..420 David Feldman, Counting plane trees, Unpublished manuscript, 1992. (Annotated scanned copy) N. J. A. Sloane, Transforms MATHEMATICA a[n_] := DivisorSum[n, MoebiusMu[n/#]*(#-1)!*SeriesCoefficient[1/(2-Exp[x + O[x]^#]), #-1]&]; a[0]=0; Table[a[n], {n, 0, 20}] (* Jean-François Alcover, Dec 03 2015, adapted from PARI *) PROG (PARI) a(n)=if(n<1, 0, sumdiv(n, d, moebius(n/d)*(d-1)!*polcoeff(1/(2-exp(x+O(x^d))), d-1))) CROSSREFS Cf. A000670. Sequence in context: A078469 A014351 A074616 * A052875 A037725 A037620 Adjacent sequences:  A006933 A006934 A006935 * A006937 A006938 A006939 KEYWORD nonn AUTHOR STATUS approved

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Last modified November 18 15:41 EST 2018. Contains 317323 sequences. (Running on oeis4.)