A057712 Number of "polyhes" of order n: a polyhe of order n is obtained by taking a polyhex made of n hexagons (A000228); cutting each of the n hexagons along a diameter and throwing away half that hexagon, in such a way that the remaining figure (made of n half-hexagons) is connected.
1, 4, 13, 60, 276, 1416, 7201, 37972, 201989, 1089815, 5929666, 32533673, 179657435
Offset: 1
References
- Enumeration of a(1)-a(8) attributed by Andrew Clarke to Brendan Owen.
Links
- Abaroth's World, Polyhes, Polyhalfhexes & Polytriamonds
- Andrew Clarke, Polyhes
- Andrew Clarke, Picture showing triangle formed by combining polyhes of orders 1, 2 and 3.
- Eric Weisstein's World of Mathematics, Polyhe
Extensions
Link updated by William Rex Marshall, Dec 16 2009
a(9)-a(13) from Aaron N. Siegel, May 23 2022