1,4

Turning over the necklace is not allowed.

M. R. Nester (1999). Mathematical investigations of some plant interaction designs. PhD Thesis. University of Queensland, Brisbane, Australia.

A001868(n)-4*A001867(n)+6*A000031(n)-4.

Cf. A001868.

Sequence in context: A026695 A052771 A056289 this_sequence A100740 A043020 A073994

Adjacent sequences: A056281 A056282 A056283 this_sequence A056285 A056286 A056287

nonn

Marks R. Nester (nesterm(AT)dpi.qld.gov.au)