0,3

See the reference for precise definition.

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

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.

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.

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

Sequence in context: A115909 A056644 A007813 this_sequence A078389 A059173 A027560

Adjacent sequences: A005306 A005307 A005308 this_sequence A005310 A005311 A005312

nonn

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