A368798 Lexicographically earliest sequence of nonnegative integers such that the doubly-infinite symmetric sequence b defined by b(n) = b(-n) = a(n) for any n >= 0 has no three equidistant equal terms.
0, 1, 1, 2, 2, 3, 2, 1, 1, 3, 3, 4, 3, 2, 4, 4, 3, 2, 3, 1, 1, 3, 4, 4, 2, 1, 1, 2, 4, 5, 5, 6, 5, 5, 2, 3, 6, 6, 4, 5, 4, 5, 5, 3, 5, 6, 4, 4, 6, 2, 6, 7, 7, 8, 7, 1, 1, 5, 6, 2, 5, 1, 1, 2, 3, 5, 2, 5, 5, 3, 2, 7, 3, 1, 1, 6, 6, 7, 3, 1, 1, 6, 6, 3, 6, 4, 2
Offset: 0
Examples
For n = 5: - the first 5 terms of the sequence are: 0, 1, 1, 2, 2, - a(5) cannot equal 0 as we would have b(-5) = b(0) = b(5), - a(5) cannot equal 1 as we would have b(-1) = b(2) = b(5), - a(5) cannot equal 2 as we would have b(3) = b(4) = b(5), - we chose a(5) = 3 as this does not induce tree equidistant equal terms.
Links
- Rémy Sigrist, Table of n, a(n) for n = 0..10000
- Rémy Sigrist, C++ program
Comments