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A365344
a(0) = 0; for n > 0, a(n) is the largest distance squared on a square spiral between a(n-1) and any previous occurrence of a(n-1). If a(n-1) has not previously occurred then a(n) = 0.
2
0, 0, 1, 0, 2, 0, 4, 0, 4, 4, 9, 0, 10, 0, 10, 4, 18, 0, 16, 0, 20, 0, 20, 4, 20, 16, 29, 0, 26, 0, 34, 0, 34, 4, 26, 20, 41, 0, 40, 0, 40, 4, 34, 72, 0, 45, 0, 41, 61, 0, 74, 0, 58, 0, 50, 0, 61, 50, 5, 0, 58, 32, 0, 85, 0, 113, 0, 89, 0, 73, 0, 89, 16, 53, 0, 85, 68, 0, 89, 61, 65, 0, 145, 0
OFFSET
0,5
LINKS
EXAMPLE
The spiral begins:
.
41--20--26--4---34--0---34 .
| | .
0 18--4---10--0---10 0 50
| | | | |
40 0 2---0---1 0 26 0
| | | | | | |
0 16 0 0---0 9 0 58
| | | | | |
40 0 4---0---4---4 29 0
| | | |
4 20--0---20--4---20--16 74
| |
34--72--0---45--0---41--61--0
.
.
a(4) = 2 as a(3) = 0 and the largest square distance between a(3) and a previous occurrence of 0 is 2 - between a(3) and a(1).
a(47) = 41 as a(46) = 0 and the largest square distance between a(46) and a previous occurrence of 0 is 41 - between a(46) and a(37). This is the first term to differ from A365343.
CROSSREFS
KEYWORD
nonn
AUTHOR
Scott R. Shannon, Oct 16 2023
STATUS
approved