2,3

B. N. Cyvin et al., Isomer enumeration of unbranched catacondensed polygonal systems with pentagons and heptagons, Match, No. 34 (Oct 1996), pp. 109-121.

Sequence in context: A030297 A045500 A109115 this_sequence A104745 A018901 A137968

Adjacent sequences: A038173 A038174 A038175 this_sequence A038177 A038178 A038179

nonn

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