A366543 a(0) = 0; for n > 0, a(n) is the largest distance squared on a square spiral between any two previous occurrences of a(n-1). If a(n-1) has not previously occurred then a(n) = 0.
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, 45, 4, 45, 16, 40, 53, 0, 50, 0, 61, 0, 65, 0, 65, 4, 65, 16, 85, 0, 68, 0, 68, 4, 65, 72, 4, 73, 0, 89, 0, 89, 4, 73, 36, 0, 130, 0
Offset: 0
Keywords
Examples
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 53 | | | | | | 40 0 4---0---4---4 29 40 | | | | 4 20--0---20--4---20--16 16 | | 34--72--0---45--0---45--4---45 . . a(4) = 2 as a(3) = 0 and the largest square distance between any previous pairs of 0's is 2 - between a(3) and a(1). a(47) = 45 as a(46) = 0 and the largest square distance between any previous pairs of 0's is 45 - between a(44) and a(31). This is the first term to differ from A365344.
Links
- Scott R. Shannon, Table of n, a(n) for n = 0..10000