OFFSET
0,4
COMMENTS
Coordinates are given on a hexagonal lattice with X-axis and Y-axis as follows:
Y
/
/
0 ---- X
LINKS
Rémy Sigrist, Table of n, a(n) for n = 0..2187
Rémy Sigrist, PARI program for A334484
Wikipedia, Arrowhead curve
EXAMPLE
The Sierpinski arrowhead curve starts (on a hexagonal lattice) as follows:
+
27\
\
+
/26
/
+----+
/24 25
/
+ +----+
23\ /20 19\
\ / \
+----+ +
22 21 /18
/
+----+ +
/4 5\ 17\
/ \ \
+ + +----+
3\ /6 16 15\
\ / \
+ + +----+ +
/2 7\ /10 11\ /14
/ \ / \ /
+----+ +----+ +----+
0 1 8 9 12 13
- hence a(3) = a(6) = a(15) = a(16) = 2.
PROG
(PARI) See Links section.
CROSSREFS
KEYWORD
nonn,look
AUTHOR
Rémy Sigrist, May 03 2020
STATUS
approved