A381856 Lexicographically earliest sequence of positive integers such that for any value k, no two sets of two or more indices at which k occurs have the same standard deviation.
1, 1, 2, 1, 2, 2, 3, 1, 3, 2, 4, 3, 3, 4, 4, 1, 5, 2, 5, 3, 4, 5, 4, 6, 1, 5, 6, 6, 2, 3, 7, 5, 6, 4, 6, 1, 7, 7, 8, 5, 7, 8, 8, 9, 6, 9, 2, 8, 3, 7, 4, 5, 9, 9, 8, 10, 9, 10, 10, 11, 7, 1, 8, 10, 11, 11, 6, 11, 9, 12, 10, 2, 12, 8, 11, 13, 12, 12, 3, 10, 13, 13
Offset: 1
Keywords
Examples
a(13) = 3: a(13) cannot be 1 as i = 4,13 would have the same standard deviation as i = 1,4,8,13 (namely 4.5). We cannot have a(13) = 2 because i = 3,6 would have the same standard deviation as i = 10,13 (namely 1.5). With a(13) = 3, we find that no two subsets of i = 7,9,12,13 have the same standard deviation, so a(13) = 3.
Links
- Pontus von Brömssen, Table of n, a(n) for n = 1..10000
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