OFFSET
1,3
COMMENTS
No three terms a(j), a(j+k), a(j+2k) (for any j and k) form an arithmetic progression.
LINKS
Giovanni Resta, Table of n, a(n) for n = 1..4000 (first 650 terms from Peter Kagey)
EXAMPLE
For n = 3:
a(3) != 1 or else midpoint((1, 1), (3, 1)) = midpoint((2, 1), (2, 1)), so
a(3) = 2.
For n = 5:
a(5) != 1 or else midpoint((1, 1), (5, 1)) = midpoint((2, 1), (4, 1));
a(5) != 2 or else midpoint((2, 1), (5, 2)) = midpoint((3, 2), (4, 1));
a(5) != 3 or else midpoint((1, 1), (5, 3)) = midpoint((3, 2), (3, 2)); so
a(5) = 4.
CROSSREFS
KEYWORD
nonn,look
AUTHOR
Peter Kagey, Apr 19 2017
STATUS
approved