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A334220
a(n) is the X-coordinate of the point at n steps forward from the origine along the space filling curve U defined in A334188; sequence A334221 gives Y-coordinates.
3
0, 1, 2, 3, 3, 3, 4, 4, 4, 5, 6, 7, 7, 7, 7, 6, 6, 6, 5, 5, 5, 5, 6, 7, 7, 7, 8, 8, 8, 9, 10, 10, 10, 10, 9, 9, 9, 8, 8, 8, 8, 9, 10, 11, 11, 11, 12, 12, 12, 13, 14, 15, 15, 15, 15, 14, 14, 14, 13, 13, 13, 13, 14, 15, 15, 15, 15, 14, 14, 14, 13, 13, 13, 12, 12
OFFSET
0,3
FORMULA
A334188(A334221(n), a(n)) = n.
EXAMPLE
The "forward" branch of curve U starting from the origin is as follows:
|
6| 25..
| |
5| 24
| |
4| 21...22...23
| |
3| 20 15...14
| | | |
2| 5....6 19 16 13
| | | | | |
1| 4 7 18...17 12
| | | |
0| 0....1....2....3 8....9...10...11
---+----------------------------------------
y/x| 0 1 2 3 4 5 6 7
- hence a(10) = a(15) = a(16) = a(17) = a(22) = 6.
PROG
(PARI) See Links section.
CROSSREFS
Sequence in context: A039728 A332965 A354779 * A234016 A029119 A178042
KEYWORD
nonn,look
AUTHOR
Rémy Sigrist, Apr 19 2020
STATUS
approved