0,4

Differences of 0. Labeled ordered partitions into 3 parts.

Number of surjections from an n-element set onto a three-element set, with n >= 3. - Mohamed Bouhamida (bhmd95(AT)yahoo.fr), Dec 15 2007

S. Plouffe, Approximations de S\'{e}ries G\'{e}n\'{e}ratrices et Quelques Conjectures}, Dissertation, Universit\'{e} du Qu\'{e}bec \`{a} Montr\'{e}al, 1992.

H. T. Davis, Tables of the Mathematical Functions. Vols. 1 and 2, 2nd ed., 1963, Vol. 3 (with V. J. Fisher), 1962; Principia Press of Trinity Univ., San Antonio, TX, Vol. 2, p. 212.

J. Riordan, An Introduction to Combinatorial Analysis, Wiley, 1958, p. 33.

J. F. Steffensen, Interpolation, 2nd ed., Chelsea, NY, 1950, see p. 54.

A. H. Voigt, Theorie der Zahlenreihen und der Reihengleichungen, Goschen, Leipzig, 1911, p. 31.

S. Plouffe, Approximations de S\'{e}ries G\'{e}n\'{e}ratrices et Quelques Conjectures}, Dissertation, Universit\'{e} du Qu\'{e}bec \`{a} Montr\'{e}al, 1992.

S. Plouffe, 1031 Generating Functions and Conjectures, Universit\'{e} du Qu\'{e}bec \`{a} Montr\'{e}al, 1992.

A. H. Voigt, Theorie der Zahlenreihen und der Reihengleichungen, Leipzig, 1911.

3!*S(n, 3). E.g.f.: (e^x-1)^3.

with (combstruct):ZL:=[S, {S=Sequence(U, card=r), U=Set(Z, card>=1)}, labeled]: seq(count(subs(r=3, ZL), size=m), m=0..25); - Zerinvary Lajos (zerinvarylajos(AT)yahoo.com), Mar 09 2007

A001117:=-6/(z-1)/(3*z-1)/(2*z-1); [Conjectured by S. Plouffe in his 1992 dissertation.]

Cf. A000919, A001118, A019538.

Sequence in context: A056375 A018214 A056268 this_sequence A055404 A132165 A074444

Adjacent sequences: A001114 A001115 A001116 this_sequence A001118 A001119 A001120

nonn,easy

njas

Extended with formula and alternate description by Christian G. Bower (bowerc(AT)usa.net), Aug 15 1998.

Simpler description from Dan Fux (dan.fux(AT)OpenGaia.com or danfux(AT)OpenGaia.com), Apr 07 2001