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A256941 a(n) is the total number of free ends of a certain configuration of line segments after n iterations (see Comments lines for definition). 2
2, 4, 8, 12, 16, 24, 28, 32, 32, 24, 32, 48, 60, 64, 68, 72, 48, 24, 32, 56, 88, 120, 120, 120, 104, 76, 80, 120, 140, 144, 148, 152, 80, 24, 32, 56, 88, 128, 168, 224, 256, 256, 212, 216, 232, 244, 224, 240, 188, 92, 80, 144, 232, 296, 296, 296, 256, 180, 176, 264, 300, 304, 308, 312, 144, 24 (list; graph; refs; listen; history; text; internal format)
OFFSET

0,1

COMMENTS

The initial pattern is a straight line segment which has 2 free ends or a(0)=2. The construction rule for the next generations are: (i) add 2 line segments (all line segments are equal length) at each free end of previous generation by arranging as "V" shaped at angle Pi/3 and symmetry connect to each free end, (ii) overlaps among differences generations are prohibited, (iii) the free ends (a(n)) are the ends of elements that do not contact or cross the other ones. It seems to be a(n) drop to 24 for n = 5, 9, 17, 33, 65,... . See illustration in the links.

The terms of this sequence should be checked! - Omar E. Pol, Apr 23 2015

LINKS

Table of n, a(n) for n=0..65.

Kival Ngaokrajang, Illustration of initial terms, n <= 11

Kival Ngaokrajang, Illustration for a(65) = 24

CROSSREFS

Cf. A194270, A194440, A194442, A220500, A220520, A220522, A256641, A256940.

Sequence in context: A256403 A308013 A260090 * A324174 A047836 A325762

Adjacent sequences:  A256938 A256939 A256940 * A256942 A256943 A256944

KEYWORD

nonn,uned

AUTHOR

Kival Ngaokrajang, Apr 19 2015

EXTENSIONS

First term suggested by Omar E. Pol, Apr 23 2015

STATUS

approved

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Last modified July 8 04:16 EDT 2020. Contains 335504 sequences. (Running on oeis4.)