

A262174


Sierpiński arrowhead curve as a triangular array starting leftward from the top, read by rows.


3



1, 2, 0, 0, 3, 4, 9, 8, 0, 5, 10, 0, 7, 6, 0, 0, 11, 0, 0, 23, 24, 13, 12, 0, 0, 22, 0, 25, 14, 0, 17, 18, 0, 21, 26, 0, 0, 15, 16, 0, 19, 20, 0, 27, 28, 69, 68, 0, 0, 0, 0, 0, 0, 0, 29, 70, 0, 67, 0, 0, 0, 0, 0, 31, 30, 0, 0, 71, 66, 0, 0, 0, 0, 0, 32, 0, 35, 36
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OFFSET

1,2


COMMENTS

The triangle up to the (1 + 2^n)th row is the nth iteration of the curve, rotated such that the curve begins at the top and continues down to the left.
As this is not a spacefilling curve, not all points on the triangular lattice are reached by the curve; these points are given the value 0.


LINKS

Max Barrentine, Table of n, a(n) for n = 1..2144
Wikipedia, Sierpiński arrowhead curve


EXAMPLE

The first 5 rows of this triangle show how this curve begins (connect the terms in numerical order):
1;
2, 0;
0, 3, 4;
9, 8, 0, 5;
10, 0, 7, 6, 0;
...


CROSSREFS

See also A163357, A163334, and A054238 for other fractal curves.
Sequence in context: A230414 A053653 A332629 * A064146 A336309 A336255
Adjacent sequences: A262171 A262172 A262173 * A262175 A262176 A262177


KEYWORD

nonn,tabl,look


AUTHOR

Max Barrentine, Sep 13 2015


STATUS

approved



