1,3

Permuting the symbols will not change the structure.

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

Sum stirling2( [(n+1)/2], k) for k from 1 to 6.

Cf. A056452.

Sequence in context: A097438 A055879 A056470 this_sequence A164904 A083849 A063501

Adjacent sequences: A056468 A056469 A056470 this_sequence A056472 A056473 A056474

nonn

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