4,1

R. V. Ditzian and L. P. Kadanoff, Series studies of the four-state Potts model, J. Phys. A 12 (1979), L229-L233.

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

Sequence in context: A059224 A088490 A069058 this_sequence A052619 A110753 A154670

Adjacent sequences: A007273 A007274 A007275 this_sequence A007277 A007278 A007279

nonn

Simon Plouffe (simon.plouffe(AT)gmail.com)