A213451 Number of fixed triangular strip polyedges with n edges.

3, 15, 69, 309, 1365, 5973, 25941, 112065, 482067, 2066583, 8834469, 37677603, 160367343

Offset: 1

Author

N. J. A. Sloane, Jun 11 2012

Keywords

• nonn
• more

References

• N. J. A. Sloane, A Handbook of Integer Sequences, Academic Press, 1973 (includes this sequence).

Links

• C. Domb, On the theory of cooperative phenomena in crystals, Advances in Phys., 9 (1960), 149-361. See page 354.

Crossrefs

Cf. A001334, A151540, A151541.

Formula

Apparently, a(n) = A001334(n)/2 for n >= 1. It needs to be clarified whether the objects described by this sequence are equivalent to the self-avoiding walks on the hexagonal lattice together with a restriction on their orientation. - Hugo Pfoertner, Jul 24 2021

Extensions

Better description and more terms from Joseph Myers, Jun 12 2012