0,1

See the reference for precise definition.

The g.f. 2*(1-2*z+2*z**2)/(-1+2*z)/(z-1) conjectured by S. Plouffe in his 1992 dissertation is unlikely to be correct.

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

T. Curtright, ``Counting symmetry patterns in the spectra of strings,'' in H. J. de Vega and N. S\'{a}nchez, editors, String Theory, Quantum Cosmology and Quantum Gravity. Integrable and Conformal Invariant Theories. World Scientific, Singapore, 1987, pp. 304-333.

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.

Sequence in context: A019101 A051890 A071109 this_sequence A002203 A097341 A142710

Adjacent sequences: A005307 A005308 A005309 this_sequence A005311 A005312 A005313

nonn

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