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A337822
Permutation of the natural numbers formed by numbering an infinite square grid by a counterclockwise diamond spiral and visiting them by a counterclockwise stair step spiral.
4
1, 2, 8, 3, 9, 20, 10, 21, 11, 4, 12, 5, 13, 14, 6, 15, 7, 16, 30, 17, 31, 18, 32, 19, 33, 52, 34, 53, 35, 54, 36, 55, 37, 22, 38, 23, 39, 24, 40, 25, 41, 42, 26, 43, 27, 44, 28, 45, 29, 46, 68, 47, 69, 48, 70, 49, 71, 50, 72, 51, 73, 100, 74, 101, 75, 102, 76
OFFSET
1,2
FORMULA
a(A102083(n)) = A102083(n) and a(A102083(n)+1) = A102083(n)+1.
EXAMPLE
The path begins:
.
---33
|
34 19--32
|
35 20---9 18--31 48
| | |
36 21--10 3---8 17--30 47
| | |
37 22 11---4 1---2 7--16 29 46
| |
38 23 12---5 6--15 28 45
| |
39 24 13--14 27 44
.
40 25 26 43
.
41 42
.
CROSSREFS
Cf. A102083.
Diamond spiral coordinates (but 0-based): A010751, A305258.
Same type of visit on other types of spirals: A334619, A337838.
Sequence in context: A076696 A011057 A082236 * A362269 A262027 A328487
KEYWORD
nonn
AUTHOR
Mohammed Yaseen, Sep 24 2020
STATUS
approved