A056339 Number of primitive (aperiodic) reversible string structures with n beads using exactly five different colors.

0, 0, 0, 0, 1, 9, 76, 542, 3523, 21392, 123680, 690541, 3756151, 20042513, 105394295, 548123440, 2826435403, 14479201301, 73794961960, 374603863517, 1895632969275, 9568915248589, 48208452866816

Offset: 1

Author

Marks R. Nester

Keywords

• nonn

Comments

A string and its reverse are considered to be equivalent. Permuting the colors will not change the structure.

References

• M. R. Nester (1999). Mathematical investigations of some plant interaction designs. PhD Thesis. University of Queensland, Brisbane, Australia. [See A056391 for pdf file of Chap. 2]

Crossrefs

Column 5 of A276544.

Cf. A056321.

Formula

A056334(n)-A056333(n).