OFFSET
0,9
COMMENTS
The curve is built by successively applying the following substitution to an initial vector (1, 0) (the two vertical copies are horizontally flipped):
*
.------>.
^ |
|* *|
* | v *
.------>. .------>.
The quadratic Koch curve is built without horizontal flip.
LINKS
Rémy Sigrist, Table of n, a(n) for n = 0..3125
Robert Ferréol (MathCurve), Courbe de Koch quadratique [in French]
Rémy Sigrist, PARI program for A340321
FORMULA
a(5^k-m) = a(m) for any k >= 0 and m = 0..5^k.
EXAMPLE
The curve starts as follows:
+---+
|12 |13
| |
+---+ +---+
|10 11 14 |15
| |
+---+ +---+
9 |8 |17 16
| |
+---+ +---+ +---+ +---+
|2 |3 |6 7 18 |19 |22 |23
| | | | | |
+---+ +---+ +---+ +---+
0 1 4 5 20 21 24 25
- so a(0) = a(1) = a(4) = a(5) = a(20) = a(21) = a(24) = a(25) = 0,
a(8) = a(9) = a(16) = a(17) = 2.
PROG
(PARI) See Links section.
CROSSREFS
KEYWORD
nonn
AUTHOR
Rémy Sigrist, Jan 04 2021
STATUS
approved