A368795 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 terms in arithmetic progression.
0, 1, 1, 2, 4, 2, 2, 1, 1, 4, 2, 4, 5, 5, 9, 3, 3, 5, 5, 10, 5, 4, 7, 3, 2, 8, 6, 2, 4, 2, 4, 7, 2, 3, 6, 5, 11, 1, 7, 15, 9, 6, 12, 10, 13, 10, 2, 13, 11, 8, 17, 9, 10, 13, 14, 1, 10, 11, 17, 15, 12, 1, 1, 5, 12, 11, 5, 6, 1, 17, 3, 15, 6, 6, 7, 6, 6, 17, 25
Offset: 0
Examples
For n = 4: - the first 4 terms of the sequence are: 0, 1, 1, 2, - a(4) cannot equal 0 due to the progression b(-4) = 0, b(0) = 0, b(4) = 0, - a(4) cannot equal 1 due to the progression b(-2) = 1, b(1) = 1, b(4) = 1, - a(4) cannot equal 2 due to the progression b(0) = 0, b(2) = 1, b(4) = 2, - a(4) cannot equal 3 due to the progression b(2) = 1, b(3) = 2, b(4) = 3, - we chose a(4) = 4 as this does not induce arithmetic progressions.
Links
- Rémy Sigrist, Table of n, a(n) for n = 0..10000
- Rémy Sigrist, Scatterplot of the first 1000000 terms
- Rémy Sigrist, C++ program
- Index entries for non-averaging sequences
Comments