0,1

Also: a bond percolation threshold probability on the triangular lattice.

S. R. Finch, Several constants arising in statistical mechanics, Annals Combinat. 3 (1999) p 323-335.

Equals 2*A019819=A019829/A019889.

0.34729635533386069770....

(PARI) 2*sin(Pi/18);

Cf. A019819.

Sequence in context: A116073 A021292 A105828 this_sequence A026248 A082089 A089961

Adjacent sequences: A130877 A130878 A130879 this_sequence A130881 A130882 A130883

cons,nonn

R. J. Mathar (mathar(AT)strw.leidenuniv.nl), Jul 26 2007