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A308312
a(n) is the last square visited by knight moves on a spirally numbered (2n-1) X (2n-1) board, moving to the lowest available unvisited square at each step.
1
1, 1, 14, 30, 69, 108, 150, 205, 264, 333, 408, 475, 553, 659, 763, 881, 1004, 1134, 1274, 1418, 1641, 1811, 1986, 2167, 2358, 2557, 2633, 2978, 2084, 2084, 2084, 2084, 2084, 2084, 2084, 2084, 2084, 2084, 2084, 2084, 2084, 2084, 2084, 2084, 2084, 2084, 2084
OFFSET
1,3
COMMENTS
A 5 X 5 board, for example, is numbered with the square spiral:
.
21--22--23--24--25
|
20 7---8---9--10
| | |
19 6 1---2 11
| | | |
18 5---4---3 12
| |
17--16--15--14--13
.
a(n) stays constant at 2084 for (2n-1) >= 57 since 2084 is also the last square visited by knight moves on a spirally numbered doubly infinite board, moving to the lowest available unvisited square at each step.
CROSSREFS
Cf. A316667.
Sequence in context: A083540 A027575 A104776 * A101960 A075208 A228124
KEYWORD
nonn
AUTHOR
Sangeet Paul, May 19 2019
STATUS
approved