A257082 a(n) is one sixth of the total number of free ends of 6 line segments expansion at n iterations (see Comments lines for definition).

1, 2, 8, 12, 28, 52, 108, 216, 448

Offset

1,2

Comments

The initial pattern consists of 6 straight line segments which are the radii of a hexagon. The next generations are scaled down by a factor of tan(Pi/6) and rotated by an angle of Pi/6. Their free ends are the ends of elements that do not contact or cross the other ones. Overlaps among different generations are prohibited. See illustration in the links.

Links

Table of n, a(n) for n=1..9.

Kival Ngaokrajang, Illustration of initial terms

Crossrefs

Cf. A238549, A256641.

Sequence in context: A268836 A027718 A115102 * A265736 A047174 A048074

Adjacent sequences: A257079 A257080 A257081 * A257083 A257084 A257085

Keyword

nonn,more

Author

Kival Ngaokrajang, May 06 2015

Status

approved