1,2

N. J. A. Sloane and Simon Plouffe, The Encyclopedia of Integer Sequences, Academic Press, 1995 (includes this sequence).

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.

R. K. Guy, Unsolved Problems in Number Theory, E20.

R. G. Stanton and P. H. Dirksen, Davenport-Schinzel sequences, Ars. Combin., 1 (1976), 43-51.

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.

A005004:=(z**3-z**2+z+1)*(z**2+z+1)/(1+z)/(z-1)**2; [Conjectured by S. Plouffe in his 1992 dissertation.]

Sequence in context: A091309 A027922 A051611 this_sequence A006218 A062839 A088940

Adjacent sequences: A005001 A005002 A005003 this_sequence A005005 A005006 A005007

nonn

N. J. A. Sloane (njas(AT)research.att.com).